Open Source .Net

Export to Excel using OpenXml

noreply@blogger.com (Raju.M) — Sun, 05 Jul 2020 02:45:00 +0000

Some situations we need to export data in Excel format. I had such situation couple of years back and I created a repository in my bitbucket account.

I thought it may be help for some one who is looking for same kind of solution while programming.

Here is the repository url
https://bitbucket.org/makhaai/exporttoexcel/src/master/

for Git Clone
git clone https://makhaai@bitbucket.org/makhaai/exporttoexcel.git

This includes there project. One model Library, One Service Library and a MVC project.

Basically we can plug List data in to it and download it as Excel document

   public FileContentResult Download() {

            List> listOfSheets = new List>() {
                    new ExcelSheet() {
                     Records =Data.GetProducts(),
                     SheetName = "ProductList 1"
                },
                 new ExcelSheet() {
                     Records =Data.GetProducts(),
                     SheetName = "ProductList 2"
                },
            };

            var excelBytes = _iExcelWriterService.GetExcelInBytes(listOfSheets);
            var fileName = string.Format("{0}_{1}.xlsx",
                                      "Products_", DateTime.Now.ToString("MMddyyyyHHmmssfff"));
            return excelBytes != null ? File(excelBytes,
                                             "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                                              fileName) : null;
        }

Online typing tool

noreply@blogger.com (Raju.M) — Sun, 05 Jul 2020 01:42:00 +0000

Apologies, I was out of track in a while. I will be starting my blogging again for good.
Last couple of month I was working on some of my personal project. couple of them will be online in weeks.
One project I wish to discuss now. Its EazyTyping.com, Its a online typing tool that uses google translation API and it having one typing game for users. Uses can mainly type Hindi, Malayalam, Guajarati etc.

Feel free to comment.

Thank you

Covariance, Contravariance and Invariance

noreply@blogger.com (StackOverflow) — Tue, 14 Jun 2016 12:34:00 +0000

Covariance and contravariance are terms that refer to the ability to use a less derived (less specific) or more derived type (more specific) than originally specified. Generic type parameters support covariance and contravariance to provide greater flexibility in assigning and using generic types. When you are referring to a type system, covariance, contravariance, and invariance have the following definitions. The examples assume a base class named Base and a derived class named Derived

Covariance

Enables you to use a more derived type than originally specified.
You can assign an instance of IEnumerable<Derived> (IEnumerable(Of Derived) in Visual Basic) to a variable of type IEnumerable<Base>.

Contravariance

Enables you to use a more generic (less derived) type than originally specified.
You can assign an instance of IEnumerable<Base> (IEnumerable(Of Base) in Visual Basic) to a variable of type IEnumerable<Derived>.

Invariance

Means that you can use only the type originally specified; so an invariant generic type parameter is neither covariant nor contravariant.
You cannot assign an instance of IEnumerable<Base> (IEnumerable(Of Base) in Visual Basic) to a variable of type IEnumerable<Derived> or vice versa.

Read more

Covariance and Contravariance in Generics

What is covariance and contravariance in c# ?

Entity Framework 7 - EF7

noreply@blogger.com (Raju.M) — Fri, 27 Feb 2015 00:34:00 +0000

Entity Framework is the popular ORM framework from Microsoft. EF7 is the next major version of Entity Framework and is still in the early stages of development and it supports Windows Store, Windows Phone and the Cloud Optimized .NET well as Mono, on both Mac and Linux, In EF7 Microsoft will be enabling providers that target non-relational data stores, such as Azure Table Storage.

EF7 will be a lightweight and extensible version of Entity Framework that just pulls forward the commonly used features. In addition, we’ll be able to include some commonly requested features that would have been difficult to implement in the existing code base, but can be included from the start in EF7.

We’ll be keeping the same patterns and concepts that you are used to in Entity Framework, except where there is a compelling reason to change them. You’ll see the same DbContext/DbSet based API but it will be built over building block components that are easy to replace or extend as needed – the same pattern we’ve used for some of the isolated components we’ve added in recent EF releases.

INTRODUCING: The Future of .NET on the Server

https://github.com/aspnet/EntityFramework/wiki/What-is-EF7-all-about
http://blogs.msdn.com/b/adonet/archive/2014/10/21/ef7-what-does-code-first-only-really-mean.aspx
http://blogs.msdn.com/b/adonet/archive/2014/05/19/ef7-new-platforms-new-data-stores.aspx

How to create CAPTCHA in MVC 5

noreply@blogger.com (Raju.M) — Wed, 13 Aug 2014 15:20:00 +0000

As a developer you probably aware of CAPTCHA, It is a type of challenge-response test used in computing to determine whether or not the user is human [CAPTCHA]
In development time we want to implement some CAPTCHA functionalists in your website, Lets check How can we do that

Basic idea is

Create a image with some letters
Save that letters in session or cache
Display our image in web page with textbox
Validate TextBox value and letter what we saved in session

Then How to create an Image?

Function to create image

 
        /// <summary>
        /// Create image Byte[]
        /// </summary>
        /// <returns></returns>
        public byte[] DrawByte()
        {
            byte[] returnByte = { };
            Bitmap bitmapImage = new Bitmap(150, 30, PixelFormat.Format32bppArgb);

            //
            // Here we generate random string
            string key = getRandomString();
            
            //
            // key string adding to Session
            HttpContext.Current.Session.Add(SessionKey, key);

            //
            // Creating image with key
            using (Graphics g = Graphics.FromImage(bitmapImage))
            {
                g.SmoothingMode = SmoothingMode.HighQuality;
                Rectangle rect = new Rectangle(0, 0, 150, 30);
                HatchBrush hBrush = new HatchBrush(HatchStyle.SmallConfetti, Color.LightGray, Color.White);
                g.FillRectangle(hBrush, rect);
                hBrush = new HatchBrush(HatchStyle.LargeConfetti, Color.Red, Color.Black);
                float fontSize = 20;
                Font font = new Font(FontFamily.GenericSerif, fontSize, FontStyle.Strikeout);
                float x = 10;
                float y = 1;
                PointF fPoint = new PointF(x, y);
                g.DrawString(key, font, hBrush, fPoint);

                using (MemoryStream ms = new MemoryStream())
                {
                    bitmapImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                    returnByte = ms.ToArray();
                }
            }
            return returnByte;
        }

Now we can chck the function to create session value or random string

        /// <summary>
        /// Generate random string value
        /// </summary>
        /// <returns></returns>
        private string getRandomString() {

            string returnString = string.Empty;
            string letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

            Random rand = new Random();

            int length = rand.Next(5, 8);
            for (int i = 0; i < length; i++)
            {
                int pos = rand.Next(0, 62);
                returnString += letters[pos].ToString();
            }
            return returnString;
        }

Here I am usign one Controller to create Image.. check below for to see my Controller

namespace CaptchaMVC.Controllers
{
    public class CaptchaController : Controller
    {
        //
        // GET: /Captcha/
        public ActionResult Index()
        {
            CaptchaHelper captchaHelper = new CaptchaHelper();
            return File(captchaHelper.DrawByte(), "image/jpeg");
        }
 }
}

From the View you call

<div class="form-group">
            <span class="control-label col-md-2"></span>
                <div class="col-md-10">
                    <img src="@Url.Action("Index","Captcha")" alt="image" />
                </div>
        </div>

I this example I created a Person Controller and displaying and validating captcha image when someone create a new person. Here I am not including everything but you can download and check the whole code

//
        // POST: /Person/Create
        [HttpPost]
        public ActionResult Create(PersonViewModel person)
        {
            try
            {
                CaptchaHelper captchaHelper = new CaptchaHelper();
                bool success = captchaHelper.Verify(person.Captcha);
                if (success)
                { 
                    //captcha success
                }

                // TODO: Add insert logic here

                return RedirectToAction("Index");
            }
            catch
            {
                return View();
            }
        }

-- Happy Coding--
Download Sample

Paging In MVC 5 with Entity Framework

noreply@blogger.com (Raju.M) — Tue, 12 Aug 2014 15:43:00 +0000

How to do Paging in MVC You can find lot of examples for paging in MVC with Entity Framework in internet. I am adding one more example. In this example you can see one partial page for paging control and ViewModel for called Pager. Here I am using AdventureWorks database Employee table to page Empoyees Following is ViewModel class, data that you need to pass to the view. Class constructor have IQueryable Datasource, It hold the data and return DataSource, TotalCount,PageSize currentpage and TotalPages.

public class Pager<T>:List<T>
    {
        public int TotalPages { get; set; }
        public int CurrentPage { get; set; }
        public int PageSize { get; set; }
        public int TotalCount { get; set; }

        public Pager(IQueryable<T> dataSource, int pageIndex, int pageSize, int totalCount)
        {
            TotalCount = totalCount;
            CurrentPage = pageIndex;
            PageSize = pageSize;
            TotalPages = (int)Math.Ceiling(TotalCount / (double)PageSize);
            this.AddRange(dataSource);
        }
    }

Model and DataContext class

 public partial class EmployeeContext : DbContext
    {
        public EmployeeContext()
            : base("name=AdventureWorksConnectionString")
        {
        }

        public virtual DbSet<DimEmployee> DimEmployees { get; set; }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
        }
    }

In Model class I am not included all the columns, Just added only columns I need..

[Table("DimEmployee")]
    public partial class DimEmployee
    {
        [Key]
        public int EmployeeKey { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Title { get; set; }
        public string EmailAddress { get; set; }
        public string DepartmentName { get; set; }
    }

EmployeeContext class return Data from database, I already Installed Entity Framework from Package Manager, But in this example I am calling one stored procedure to get the data using EF. Its for I am not taking the whole data from database.. Just taking what I want to display. Here we need to pass the limit of data we want.

USE [AdventureWorksDW2008R2]
GO
/****** Object:  StoredProcedure [dbo].[getEmployeeByPageNumber]    Script Date: 08/12/2014 14:24:29 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:  <Raju Melveetilpurayil>
-- Create date: <Create Date,,>
-- Description: <Get rows by row between limit>
-- =============================================
ALTER PROCEDURE [dbo].[getEmployeeByPageNumber]
 -- Add the parameters for the stored procedure here
 @Start INT,
 @End INT,
 @TotalCount INT OUTPUT
AS
BEGIN
 -- SET NOCOUNT ON added to prevent extra result sets from
 -- interfering with SELECT statements.
 SET NOCOUNT ON;
SELECT @TotalCount=COUNT(*) FROM dbo.DimEmployee
SELECT [EmployeeKey]
      ,[FirstName]
      ,[LastName]
      ,[Title]
      ,[EmailAddress]
      ,[DepartmentName] FROM 
(
 SELECT ROW_NUMBER() OVER(ORDER BY EmployeeKey) ROW_NUM, * FROM DimEmployee
 ) AS K
 WHERE ROW_NUM >@Start AND ROW_NUM <=@End
  
END

Now we can see our MVC pages. Here is a partial page it only meant to display paging controls. The advantage of this control and model are generic, so we can pass any datasouce to do paging.


   @{
         double _pageCount = ((double)((Model.TotalCount-1) / Model.PageSize));
         int pageCount = _pageCount - (Math.Round(_pageCount)) != 0 ? (int)(_pageCount + 1) : (int)_pageCount;

         //
         // disable class for next and previous button if there is no previous and next
         string classNameForNext = Model.CurrentPage == _pageCount ? "disabled" : string.Empty;
         string classNameForPrevious = Model.CurrentPage == 1 ? "disabled" : string.Empty;
    }

        @if (classNameForPrevious == string.Empty){
         @Html.ActionLink("« Prev", "Index", new { page = (Model.CurrentPage - 1) })}
        else{
        « Prev}

    
@for (int pages = 1; pages <= pageCount; pages++)
    {
        //
        //adding active class to current page
        string active = "";
        if (pages == Model.CurrentPage) { active = "active"; }
@Html.ActionLink(pages.ToString(), "Index", new { page = pages })
}

        @if (classNameForNext == string.Empty){
            @Html.ActionLink("Next »", "Index", new { page = (Model.CurrentPage + 1) })}
        else{
           Next »
        }

form the Index.cshtml we pass Model to the partial page. From the Model partial page read class properties TotalPage,CurrentPage.. and generate page numbers and next and previous buttons Passing Model to partial Page

<tr>
     <td colspan="5">
        @Html.Partial("_PagingPartial",Model)
     </td>
</tr>

Ok Now we can see the whole Index.cshtml

@model EFMVCSample.ViewModel.Pager<EFMVCSample.Models.DimEmployee>
@{
    ViewBag.Title = "Employee";
}
<table class="table">
         <tr>
            <th>FirstName</th>
            <th>LastName</th>
            <th>Title</th>
            <th>EmailAddress</th>
            <th>DepartmentName</th>
        </tr>
            @foreach (EFMVCSample.Models.DimEmployee employee in Model.AsQueryable().ToList())
            {
                <tr>
                    <td>@employee.FirstName</td>
                    <td>@employee.LastName</td>
                    <td>@employee.Title</td>
                    <td>@employee.EmailAddress</td>
                    <td>@employee.DepartmentName</td>
                </tr>
            }
    <tr>
        <td colspan="5">
            @Html.Partial("_PagingPartial",Model)
        </td>
    </tr>
</table>

So we can see PagingController to see how controller works

public class PagingController : Controller
    {
        private List<DimEmployee> AllEmpoyees { get; set; }

        //
        // GET: /Paging/
        public ActionResult Index(int? page)
        {
            int pageno = 0;
            pageno = page == null ? 1 : int.Parse(page.ToString());

            int pageSize = 15;
            int totalCount = 0;



            using (var db = new EmployeeContext())
            {
                int limitEnd = pageno * pageSize;
                int limitStart = limitEnd - pageSize;

                //
                //calling stored procedure to get the total result count

                var start = new SqlParameter("@Start", limitStart);
                var end = new SqlParameter("@End", limitEnd);

                //
                // setting stored procedure OUTPUT value
                // This return total number of rows, and avoid two database call for data and total number of rows 
                var spOutput = new SqlParameter
                {
                    ParameterName = "@TotalCount",
                    SqlDbType = System.Data.SqlDbType.BigInt,
                    Direction = System.Data.ParameterDirection.Output
                };

                //
                //calling stored procedure to get paged data.
                AllEmpoyees = db.Database.SqlQuery<DimEmployee>(
                                                "getEmployeeByPageNumber @Start,@End,@TotalCount out",
                                                start, end, spOutput)
                                                .ToList();

                //
                // setting total number of records
                totalCount = int.Parse(spOutput.Value.ToString());

            }
            Pager<DimEmployee> pager = new Pager<DimEmployee>(AllEmpoyees.AsQueryable(), pageno, pageSize, totalCount);
            return View(pager);

        }
 }

Depend on page number, Controller create pageno,pageSize and call stored procedure to get data between limit.

 var spOutput = new SqlParameter
                {
                    ParameterName = "@TotalCount",
                    SqlDbType = System.Data.SqlDbType.BigInt,
                    Direction = System.Data.ParameterDirection.Output
                };

//
//calling stored procedure to get paged data.
AllEmpoyees = db.Database.SqlQuery<DimEmployee>("getEmployeeByPageNumber @Start,@End,@TotalCount out",start, end, spOutput).ToList();

Download example

CodeProject

How to get stored procedure OUTPUT Parameters in Entity Framework

noreply@blogger.com (Raju.M) — Sun, 10 Aug 2014 21:38:00 +0000

Calling stored procedure from Entity framework code first is not an issue. Its explained very well in Entity Framework tutorials as well [Here] , Let see how to call custom stored procedure from C#

This is my stored procedure to return total number of employes from database

USE [AdventureWorksDW2008R2]
GO
/****** Object:  StoredProcedure [dbo].[getEmployeeCount] 
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author: Raju Melveetilpurayil
-- Create date: 
-- Description: Get total number of employes from AdventureWorksDW2008R2 database
-- =============================================
ALTER PROCEDURE [dbo].[getEmployeeCount] 
AS
BEGIN
 SET NOCOUNT ON;

 SELECT COUNT(*)AS EmpCount FROM dbo.DimEmployee
END

--
--

Now we can check how to call above stored procedure from C#


using (var db = new EmployeeContext())
{
 var totalNumberOfEmployes = db.Database.SqlQuery<int>("getEmployeeCount").ToList();
 int totalNumber = totalNumberOfEmployes.FirstOrDefault<int>();
}

So we can call a stored procedure with some parameter including OUTPUT parameter

USE [AdventureWorksDW2008R2]
GO
/****** Object:  StoredProcedure [dbo].[getEmployeeByPageNumber]    Script Date: 08/10/2014 22:25:18 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:  <Raju Melveetilpurayil>
-- Create date: <Create Date,,>
-- Description: <Get rows by row between limit>
-- =============================================
ALTER PROCEDURE [dbo].[getEmployeeByPageNumber]
 -- Add the parameters for the stored procedure here
 @Start INT,
 @End INT,
 @TotalCount INT OUTPUT
AS
BEGIN
 -- SET NOCOUNT ON added to prevent extra result sets from
 -- interfering with SELECT statements.
 SET NOCOUNT ON;
SELECT @TotalCount=COUNT(*) FROM dbo.DimEmployee
SELECT [EmployeeKey]
      ,[FirstName]
      ,[LastName]
      ,[Title]
      ,[EmailAddress]
      ,[DepartmentName] FROM 
(
 SELECT ROW_NUMBER() OVER(ORDER BY EmployeeKey) ROW_NUM, * FROM DimEmployee
 ) AS K
 WHERE ROW_NUM >@Start AND ROW_NUM <=@End
  
--
--
END

Actually the above script I am using for to get data between some limit.. I will use this same script in my later articles for How to do paging in MVC 5 We need to pass one SqlParameter parameter and set its direction to System.Data.ParameterDirection.Output, after executing the function SqlParameter hold the OUTPUT data.

var spOutput = new SqlParameter {
                    ParameterName = "@TotalCount",
                    SqlDbType = System.Data.SqlDbType.BigInt,
                    Direction = System.Data.ParameterDirection.Output 
                };

we pass other parameter like normal SqlParameter

var start = new SqlParameter("@Start", limitStart);
var end = new SqlParameter("@End", limitEnd);

db.Database.SqlQuery help us to call raw Sql from entity framework The whole code

//
// calling stored procedure to get the total result count

var start = new SqlParameter("@Start", limitStart);
var end = new SqlParameter("@End", limitEnd);
               
//
// setting stored procedure OUTPUT value
// This return total number of rows, and avoid two database call for data and total number of rows 
var spOutput = new SqlParameter {
                    ParameterName = "@TotalCount",
                    SqlDbType = System.Data.SqlDbType.BigInt,
                    Direction = System.Data.ParameterDirection.Output 
                };
//
//calling stored procedure to get paged data.
  List<DimEmployee> AllEmpoyees = db.Database.SqlQuery<DimEmployee>(
                               "getEmployeeByPageNumber @Start,@End,@TotalCount out",
                                start, end, spOutput)
                                .ToList();
//
// setting total number of records
totalCount = int.Parse(spOutput.Value.ToString());


//
//

Happy programming ..

How to return JSON from WebAPI 2

noreply@blogger.com (Raju.M) — Sun, 27 Jul 2014 12:02:00 +0000

Nowadays JSON is more common than XML, Most of the JavaScript frameworks work well with JSON contents, AngularJS is an excellent example. Default WebAPI have IEnumerable<string> Get() and string Get(int id) methods

Take a look

public class DefaultController : ApiController
    {
        // GET api/default2
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/default2/5
        public string Get(int id)
        {
            return "value";
        }

        // POST api/default2
        public void Post([FromBody]string value)
        {
        }

        // PUT api/default2/5
        public void Put(int id, [FromBody]string value)
        {
        }

        // DELETE api/default2/5
        public void Delete(int id)
        {
        }
    }

If you wish to return a JSON instead of string from WebAPI 2 may face some issues, So How can it resolved? You can return HttpResponseMessage instead of string or IEnumerable.. If you want to read more check this out Two ways to work with HTTP responses in ApiController Below code will return JSON string for you

       [Route("api/Default/GetProductLookup/{id}")]
        public HttpResponseMessage GetProductLookup(string id)
        {
            string json = "Your JSON String";
            var response = Request.CreateResponse(HttpStatusCode.OK);
            response.Content = new StringContent(json, Encoding.UTF8, "application/json");
            return response;
        }

Here is the whole class

public class DefaultController : ApiController
    {
        // GET api/default2
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/default2/5
        public string Get(int id)
        {
            return "value";
        }

        [Route("api/Default/GetProductLookup/{id}")]
        public HttpResponseMessage GetProductLookup(string id)
        {
            string json = "Your JSON String";
            var response = Request.CreateResponse(HttpStatusCode.OK);
            response.Content = new StringContent(json, Encoding.UTF8, "application/json");
            return response;
        }

        // POST api/default2
        public void Post([FromBody]string value)
        {
        }

        // PUT api/default2/5
        public void Put(int id, [FromBody]string value)
        {
        }

        // DELETE api/default2/5
        public void Delete(int id)
        {
        }
    }

How to Add Json MIME type in IIS 7.5

noreply@blogger.com (Raju.M) — Tue, 04 Mar 2014 01:52:00 +0000

Today .NET Web Development and Tools group at Microsoft released Customer Tech Preview (CTP2) release of Visual Studio 2013 Update 2 contains a new JSON editor. "New JSON editor features in Visual Studio 2013 Update 2 CTP2"

So I Installed CTP2 updated for my visual studio 2013 to see how JSON template works and all.

{
   "Person":[
      {
         "FirstName":"Raju",
         "LastName":"Melveetilpurayil",
         "Languages":[
            {
               "id":"1",
               "name":"C#"
            },
            {
               "id":"2",
               "name":"Javascript"
            },
            {
               "id":"3",
               "name":"C++"
            }
         ]
      }
   ]
}

It was ok. but when I tried to read my json file from browser (localhost url) I am started getting some some errors, I knew I got one exception because last day I got my laptop after repair, everything is new and ready for first run, I do not installed IIS on my machine.

This was the exception
HTTP Error 404.3 - Not Found The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map. Installed IIS 7.5 and Added MIME type for JSON, default there is no JOSN type in IIS 7.5

How To Add MIME Type In IIS 7.5

1: Open IIS Manager [ in RUN type inetmgr] press Enter

2: Click on MIME Types

3: Right click and Select Add

DONE, You added MIME type for JSON in IIS.

I ran my JSON file again and still got some other exceptions. I started goggling, finally I found Solution that we need to give to run JSON
To allow the IIS to serve JSON files, your need to add some configuration in web.config:

<system.webServer>
      <staticContent>
        <mimeMap fileExtension=".json" mimeType="application/json" />
      </staticContent>
</system.webServer>

Visual Studio 2012 and .NET Framework 4.5 is Released

noreply@blogger.com (Raju.M) — Wed, 15 Aug 2012 23:50:00 +0000

Microsoft announced the availability of Microsoft .NET Framework 4.5 and Visual Studio 2012 today.http://blogs.msdn.com/b/dotnet/archive/2012/08/15/announcing-the-release-of-net-framework-4-5-rtm-product-and-source-code.aspx
You can download Visual Studio 2012 from http://www.microsoft.com/visualstudio/11/en-us
and take a look on Whats new in Framework 4.5 http://msdn.microsoft.com/library/ms171868(v=vs.110).aspx

What's New in ASP.NET 4.5 and Visual Studio 2012 http://www.asp.net/vnext/overview/whitepapers/whats-new
Learn What's New By Tutorial Visual Studio 2012 http://msdn.microsoft.com/en-US/library/hh420390.aspx#whatsnew_scenario
Reference Source Code Center [RSCC] http://referencesource.microsoft.com/
Releasing the source code for the .NET Framework 4.5 libraries http://referencesource.microsoft.com/netframework.aspx

Decimal to fraction convertion c#

noreply@blogger.com (Raju.M) — Mon, 13 Aug 2012 00:05:00 +0000

I think there is nothing to explain below code. I used this code snippet to calculate the fractional value of a decimal number. Might help someone.

        /// 
        ///  return fraction from decimal value
        /// 
        /// 
        /// string
        /// 
        /*
         * logic:
         * x=5.333
         * 10x=53.33
         * 10x-x=Math.Round(53.33-5.333)
         * 9x=48
         * x=48/9
         * find common factor
         * divide both side by commen factor [ nuerator and denominator]
         * return faction
         * */
 public string DecimalToFraction(decimal decimalvalue)
        {
            decimal decimalTemp = decimalvalue;
            string returnDecimalvalue = string.Empty;
            decimal temp = decimalTemp * 10;
            decimal numerator = System.Decimal.Round(temp - decimalTemp);
            decimal denominator = 10 - 1;

            int comFact = getCommonFactor((int)numerator, (int)denominator);
            returnDecimalvalue = (numerator / comFact).ToString() + "/" + (denominator / comFact).ToString();
            return returnDecimalvalue;
        }

function to find the common factor

private int getCommonFactor(int a, int b)
        {
            int count;
            while (b != 0)
            {
                count = a % b;
                a = b;
                b = count;
            }
            return a;
        }

Thanks.

Unlimited Scroll in ASP.Net DataList Control

noreply@blogger.com (Raju.M) — Tue, 29 Nov 2011 02:46:00 +0000

Unlimited scroll is not a big deal, for example facebook news feed its scroll when user reach bottom of the page. Actually client side script check the scroll position the container, if the position is in bottom, the scripts request content form server and update the container. In here the container is a DIV tag, named holder, and put some style tag height, width and overflow.holder is hold the DataList

CSS for the holder.

Here I used Northwind database Products Table to demonstrate the unlimited scroll in this article and used a Handler page, First time page loads with 10 records in DataList, take a look below.

        if (!IsPostBack)
        {
            DataClass data = new DataClass();
            DataList1.DataSource = data.FirstTenRecords();
            DataList1.DataBind();
        }

And in client side I set current item count to 10 and next item count to 0.

var current=10;
var next=0;

and call function for load next form javascript, it’s nothing but calling server via AJAX, ie requesting Handler page with a query string of start and next. below image shows how the request url form client, I used firebug to show requests

lets look on loadNext

 var loadNext = function () {
            next = current + 10;
            $.ajax({
                url: "Handler.ashx?start=" + current + "&next=" + next,
                success: function (data) {
                    $("#DataList1").append(data);
                }
            });
            current = current + 10;
        };

Before calling the Handler page set next, after set current to current+10

  next = current + 10;
  current = current + 10;

To get the data from a specific row number I used a stored procedure, it will return my data, I want to send number of position, if I send start=10&next=20, It will return 10th to 20th row form the database.

USE [Northwind]
GO
/****** Object:  StoredProcedure [dbo].[ProductPages]    Script Date: 11/28/2011 12:03:17 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[ProductPages]
(
 @start int,
 @next int
) 
AS
BEGIN
SELECT ProductID,ProductName,UnitPrice FROM
(
   SELECT ROW_NUMBER() OVER(ORDER BY ProductID,ProductName,UnitPrice) NUM,
   * FROM Products
) A 
WHERE NUM >@start AND NUM <=@next
END

Now let take a look on how its work. everything works depends on holders scroll function. script check the scroll position of the container is bottom or not, if it on bottom, function call loadNext().

 $(document).ready(function () {
            $("#holder").scroll(function () {
                if ($(this)[0].scrollHeight - $(this).scrollTop() == $(this).outerHeight()) {
                    loadNext();
                }
            });
        });

Handler page is nothing, like a aspx page.Its call a class file DataClass, DataClass is simple class file to reduce bulky code in Handler page. It call the DataLayer and return the data from database, after do some format to fill on the DataList and write it on response.

public void ProcessRequest(HttpContext context)
    {
        string startQstring = context.Request.QueryString["start"];
        string nextQstring = context.Request.QueryString["next"];
        //null check
        if ((!string.IsNullOrWhiteSpace(startQstring)) && (!string.IsNullOrWhiteSpace(nextQstring)))
        {
            //convert string to int
            int start = Convert.ToInt32(startQstring);
            int next = Convert.ToInt32(nextQstring);
            
            //setting content type
            context.Response.ContentType = "text/plain";
            DataClass data = new DataClass();
            //writing response
            context.Response.Write(data.GetAjaxContent(start, next));
        }
    }

There is only one class file. But I put there class on that file.
1:DataClass :

Contain two function On handler page we are calling first function GetAjaxContent(start,end) it retrun the records from database.
2nd function loaad data on Page_Load even

2: Provide : Provide SqlConnection from web.config
3:DBHelper : Data layer Take a look

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

/// 
/// Summary description for DataClass
/// 
/// 


public class DataClass
{
    public DataClass()
    {
    }
    /// 
    ///  return rows depend on position
    ///  if you need 10th to 20th you need to pass start=10 and end=20
    /// 
    /// 
database start position of one row
    /// 
database end position of one row
    /// 
    public string GetAjaxContent(int start, int end)
    {
        string result = string.Empty;
        //adding sp params with values in Dictionary entry.
        Dictionary keyValPair = new Dictionary();
        keyValPair.Add("@start", start);
        keyValPair.Add("@next", end);

        DBHelper DBHelper = new DBHelper();
        //passing the Stored Procedure name and keyvalue pair
        DataTable dataTable = DBHelper.GetTable("ProductPages", keyValPair);
        if (dataTable.Rows.Count > 0)
        {
            for (int i = 0; i < dataTable.Rows.Count; i++)
            {
                result += string.Format(@"
                                                        
                                                            
                                                                

                                                                    {0} {1} {2}
                                                                

", dataTable.Rows[i][0].ToString(), dataTable.Rows[i][1].ToString(), dataTable.Rows[i][2].ToString());
            }

        }
        //this string is going to append on Datalist on client.
        return result;
    }
    /// 
    /// function to bind data on page load
    /// 
    /// 
    public DataTable FirstTenRecords()
    {
        Dictionary keyValPair = new Dictionary();
        keyValPair.Add("@start", 0);
        keyValPair.Add("@next", 10);

        DBHelper DBHelper = new DBHelper();
        DataTable dataTable = DBHelper.GetTable("ProductPages", keyValPair);
        return dataTable;
    }
}

/// 
/// return sqlconnection string formweb.config file
/// 
public class Provider
{
    public static SqlConnection GetConnection()
    {
        return new SqlConnection(ConfigurationManager.AppSettings["SqlConnectionString"]);
    }
}
/// 
/// Data layer
/// 
public class DBHelper
{
    public DBHelper()
    { }

    SqlConnection con;
    SqlCommand cmd;
    SqlDataAdapter adapter;
    public DataTable GetTable(string SPName, Dictionary SPParamWithValues)
    {
        DataTable dataTable = new DataTable();
        try
        {
            con = Provider.GetConnection();
            //open DB connection
            con.Open();
            cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Connection = con;
            cmd.CommandText = SPName;
            foreach (KeyValuePair paramValue in SPParamWithValues)
            {
                cmd.Parameters.AddWithValue(paramValue.Key, paramValue.Value);
            }
            adapter = new SqlDataAdapter(cmd);
            adapter.Fill(dataTable);
        }
        finally
        {
            //close connection string
            con.Close();
        }
        return dataTable;
    }
}

If it not display properly please use the images

Download Source

Download full source code

Download Microsoft® Visual Studio® 11 Developer Preview

noreply@blogger.com (Raju.M) — Fri, 30 Sep 2011 11:16:00 +0000

Overview
Visual Studio 11 Developer Preview is an integrated development environment that seamlessly spans the entire life cycle of software creation, including architecture, user interface design, code creation, code insight and analysis, code deployment, testing, and validation. This release adds support for the most advanced Microsoft platforms, including the next version of Windows (code-named "Windows 8") and Windows Azure, and enables you to target platforms across devices, services, and the cloud. Integration with Team Foundation Server allows the entire team, from the customer to the developer, to build scalable and high-quality applications to exacting standards and requirements.

Visual Studio 11 Developer Preview is prerelease software and should not be used in production scenarios.

This preview enables you to test updates and improvements made since Visual Studio 2010, including the following:

Support for the most advanced platforms from Microsoft, including Windows 8 and Windows Azure, as well as a host of language enhancements.
New features such as code clone detection, code review workflow, enhanced unit testing, lightweight requirements, production intelliTrace™, exploratory testing, and fast context switching.

This preview can be installed to run side by side with an existing Visual Studio 2010 installation. The preview provides an opportunity for developers to use the software and provide feedback before the final release. To provide feedback, please visit the Microsoft Connect website.

The .NET Framework 4.5 Developer Preview is also installed as part of Visual Studio 11 Developer Preview.

Note: This prerelease software will expire on June 30, 2012. To continue using Visual Studio 11 after that date, you will have to install a later version of the software.

In order to develop Metro style applications, the Visual Studio 11 Developer Preview must be installed on the Windows Developer Preview with developer tools English, 64-bit. Developing Metro style applications on other Preview versions of Windows 8 is not supported.

System requirements

Supported Operating Systems: Windows 7, Windows Server 2008 R2

Windows 7 (x86 and x64)
Windows 8 (x86 and x64)
Windows Server 2008 R2 (x64)
Windows Server Developer Preview (x64)

Supported Architectures:

32-bit (x86)
64-bit (x64)

Hardware Requirements:

1.6 GHz or faster processor
1 GB of RAM (1.5 GB if running on a virtual machine)
5.5 GB of available hard disk space
5400 RPM hard drive
DirectX 9-capable video card running at 1024 x 768 or higher display resolution

What is new in VS2011

Source Download Microsoft® Visual Studio® 11 Developer Preview

Download Microsoft Visual Studio 2010 SP1

noreply@blogger.com (Raju.M) — Tue, 30 Aug 2011 09:45:00 +0000

MIcrosoft Visual Studio 2010 SP1 RTM
Microsoft released Microsoft Visual Studio 2010 SP1 RTM for all vs2010 products to developers.
Online Installer
Offline Installer
Offline Installer is an .ISO file. You can use daemon tools [download from here] to create virtual IDE devices.

Checking Username Availability using ASP.net AJAX

noreply@blogger.com (Raju.M) — Wed, 02 Feb 2011 01:04:00 +0000

Checking username in user registration page is common thing in these days. Now we can check how to this using AJAX., ie Check username availability without postback. To achieve this you need to know about Ajax. Ajax is Asynchronous JavaScript and XML. AJAX is the art of exchanging data with a server, and update parts of a web page - without reloading the whole page [more].

Here I use two Class files and one Generic handler page to simplify code.

1: AjaxHelper
2: DataBaseHelper
3: Handler.ashx

Do not get confused, Client side javascript communicating sever with the help of Handler file, ie we send request to handler file, In the Handler file we create one instance of AjaxHelper Class and communicate with database with the help of DataBaseHelper Class

First we can check the sample images

User in Database

Now we can check how to send request to Handler Page, ie we do ajax calls to server, see the script below

Above we requested the handler file, Now we are going to check what handler file do when a request come from the client side.
first handler file check the query string. after create an instance of AjaxHelper class, it contain one boolean function called CheckUserNameAvailable(stirng username). if the value of CheckUserNameAvailable is true, it send response as "Available" else it send "Not Available".

public void ProcessRequest(HttpContext context)
    {
        HttpRequest request = context.Request;
        HttpResponse response = context.Response;
        if (!string.IsNullOrEmpty(request.QueryString["uname"]))
        {
            AjaxHelper ajaxHelper = new AjaxHelper();
            bool available = ajaxHelper.CheckUserNameAvailable(request.QueryString["uname"]);
            if (available)
            {
                response.Write("Username Available");
            }
            else
            { response.Write("Username Not Available"); }
        }

    }

Next is what is happening AjaxHelper Class, here is do not use any store procedure, if you need you can use SP. I already mentioned that this class contain only one method, public bool CheckUserNameAvailable(string username)
in this class I select the users in usertable which username is equal to requested username.

public class AjaxHelper
{
    public AjaxHelper()
    {
    }
    public bool CheckUserNameAvailable(string username)
    {
        DataBaseHelper DBHelper = new DataBaseHelper();
        string cmdString = string.Format("SELECT username FROM usertable  WHERE username ='{0}'", username);
        string user = Convert.ToString(DBHelper.ExecuteScalar(cmdString));
        if (string.IsNullOrEmpty(user))
            return true;
        else
            return false;
    }
}

Check the DataBaseHelper Class, in DataBaseHelper class we read connection string form web.config file. then create sql connection, set sql command object, open sql connection, execute sql command, close sql connection, dispose command and connection.

public class DataBaseHelper
{
    SqlConnection con;
    SqlCommand cmd;

    public DataBaseHelper()
    {
    }
    public object ExecuteScalar(string commandText)
    {
        con = Provider.GetConnection();
        cmd = new SqlCommand(commandText, con);
        con.Open();
        try
        {
            return cmd.ExecuteScalar();
        }
        catch
        { throw; }
        finally
        {
            cmd.Dispose();
            con.Close();
            con.Dispose();
        }
    }
}




public class Provider
{
    public static SqlConnection GetConnection()
    {
        return new SqlConnection(ConfigurationManager.AppSettings["sqlConn"]);
    }
}

Connection string in Web.Config

Download source username availability in asp.net Ajax

Javascript Countdown timer

noreply@blogger.com (Raju.M) — Tue, 25 Jan 2011 23:33:00 +0000

This post is mainly to understand, how to program a countdown timer using javascript. if you need to study more about javascript and javascript timer function go to w3schools.com and select Learn JavaScript.

Here I use two funtion to ActivateTimer() and Timer()

check the script

Check the Output

Example URL

Full code file

<HTML>
  <BODY>
  <div>
        <div ID="Label1" style="font-size:24pt;font-weight:bold;"></div>
        <input type="button" onclick="ActivateTimer();" value="Activate" />
        <script language="javascript" type="text/javascript">
            var min = 1;
            var sec = 59;
            var timer;
            var timeon = 0;
            function ActivateTimer() {
                if (!timeon) {
                    timeon = 1;
                    Timer();
                }
            }
            function Timer() {
                var _time = min + ":" + sec;
                document.getElementById("Label1").innerHTML =_time;
                if (_time != "0:0") {
                    if (sec == 0) {
                        min = min - 1;
                        sec = 59;
                    } else {
                        sec = sec - 1;
                    }
                    timer = setTimeout("Timer()", 1000);
                }
                else {
                    alert("Time is Over");
                }
            }
        </script>

    </div>
 </BODY>
</HTML>

Limiting file size or getting file size of Upload file in ASP.Net

noreply@blogger.com (Raju.M) — Tue, 25 Jan 2011 23:22:00 +0000

this is a small code snippet to limit file size on file upload

Asp.Net FileUpload control's FileBytes.Length returns file size in Bytes.
Here we want file size in MB. so we want to divide size by 1024*1024.

ie
1024 kilobytes = 1 megabyte (MB)
1 Kilobyte = 1024 bytes

protected void Button1_Click(object sender, EventArgs e)
    {
        //checking size 
        double fileSize =(double) FileUpload1.FileBytes.Length;
        double fileinMB = fileSize / (1024 * 1024);
        if (fileinMB > limit)
        {
            Response.Write("Size is limited to 2MB");
        }
        else
        {
        //upload file
            Response.Write("Uploaded");
        }
       
    }

Image Handling In ASP.Net

noreply@blogger.com (Raju.M) — Sat, 06 Nov 2010 23:47:00 +0000

Contents

Introduction
Store Image

In Database
In Folder

Display Image in Image Control, GridView and DataList

From Database
From Folder

Creating Thumbnails
Adding Watermark Text on Image
Adding Image as Watermark

Introduction

In this Article I am going to explain how to handle image in ASP.Net. I seen lot of question regarding "How to save and display image from database in ASP.Net" in different .net discussing forums. I think it must be helpful for beginners to solve their problems regarding images in ASP.Net.

Store Images

We can store images in Database and project folders. If it is in Database the datatype of image data is "image" , now we can check the Database design

In Database

here I used create a store procedure to save image in database.

CREATE PROCEDURE [dbo].[sp_UploadImage]
@imageData as image
AS
BEGIN
INSERT INTO Images (imageData) VALUES(@imageData)
END

Now we can look how to save image in Database. we need one FileUpload Control to select file. and need to check file extension to verify uploading file is image or not. below script function "valiadate();" check the file is image or not, ie we check the file extensions with javascript.

Javascript to check Upload file extension

Now check the .aspx page

Now server side code. Reading bytes value from FileUpload Control and pass that value with store procedure name in to a HashTable. that hashtable send to DataBaseHelper Class file to save image in Database.

 protected void btnUploadImage_Click(object sender, EventArgs e)
    {
        //server side checking
        if (FileUpload1.PostedFile.ContentType.ToLower().StartsWith("image") && FileUpload1.HasFile)
        {
            Hashtable imageHash = new Hashtable();
            imageHash.Add("@imageData", FileUpload1.FileBytes);
            DataBaseHelper DBHelper = new DataBaseHelper();
            //storing image in to DataBase
            DBHelper.ExecuteNonQuery("sp_UploadImage", imageHash);
        }
    }

Database with image data

In Folder Saving folder is simple to compare saving in Database. FileUpload control have SaveAs() method to save file. here I save images in "savedImages" folder. We are not keeping any values in database. At the time of display image we pick images from folder using DirectoryInfo and FileInfo Class or Directory.GetFiles Methord

protected void btnUploadToFolder_Click(object sender, EventArgs e)
    {
        //save file in folder
        if (FileUpload1.PostedFile.ContentType.ToLower().StartsWith("image") && FileUpload1.HasFile)
        {
            string savelocation = Server.MapPath("savedImages/");
            string fileExtention = System.IO.Path.GetExtension(FileUpload1.FileName);
            //creating filename to avoid file name conflicts.
            string fileName = Guid.NewGuid().ToString();
            //saving file in savedImage folder.
            string savePath = savelocation + fileName + fileExtention;
            FileUpload1.SaveAs(savePath);
        }
    }

Preview of saved images in folder

Display Images in Image Control, GridView and DataList To display image from Database is not simple as displaying from folders. because we previously saved image as byte in Database. From Database To display image, we need to change byte data to Image, to convert byte data to image we need to use a separate page, here I am using a Generic Handler page to show image from Database. In that Generic Handler page we take image byte from Database and render in that Handler page and set image controls src or ImageUrl to that Generic Handler page for example it work like this

//from database
Image1.ImageUrl="Handler.aspx?id=1";
//from folder
Image1.ImageUrl="savedImages/ca34fa6c-8321-492c-938b-5413781bdcde.png";

Display image in Generic Handler page Method 1

  
   public void ProcessRequest (HttpContext context) {
        HttpRequest request = context.Request;
        if (!string.IsNullOrEmpty(request.QueryString["id"]))
        {
            //this hash table contain the SP parameter
            Hashtable hash = new Hashtable();
            hash.Add("@imageID", request.QueryString["id"]);
            DataBaseHelper DBHelper = new DataBaseHelper();

            //DBHelper.SQLExecuteNonQuery(procedure_name,command_parameters) return the object data.
            // casting return value to byte[]
            byte[] imageByte = (byte[])DBHelper.SQLExecuteNonQuery("sp_getImage", hash);
            //creating object of image
            System.Drawing.Image b;
            //creating object of bitmap
            Bitmap bitMap = null;
            //checking byte[] 
            if (imageByte != null && imageByte.Length > 0)
            {
                //creating memoryStream object
                using (MemoryStream mm = new MemoryStream())
                {
                    //wrting to memoryStream
                    mm.Write(imageByte, 0, imageByte.Length);
                    b = System.Drawing.Image.FromStream(mm);
                    bitMap = new System.Drawing.Bitmap(b, b.Width, b.Height);
                    //creating graphic object, to produce High Quality images.
                    using (Graphics g = Graphics.FromImage(bitMap))
                    {
                        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                        g.SmoothingMode = SmoothingMode.HighQuality;
                        g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                        g.DrawImage(bitMap, 0, 0, b.Width, b.Height);
                        g.Dispose(); b.Dispose(); mm.Dispose();
                        //changing content type of handler page
                        context.Response.ContentType = "image/jpeg";
                        //saving bitmap image
                        bitMap.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                        bitMap.Dispose();
                    }
                }
            }
        }
    }

Method 2 You can also use this code to render image in Handler page

public void ProcessRequest (HttpContext context) {
        HttpRequest request = context.Request;
        if (!string.IsNullOrEmpty(request.QueryString["id"]))
        {
            //this hash table contain the SP parameter
            Hashtable hash = new Hashtable();
            hash.Add("@imageID", request.QueryString["id"]);
            DataBaseHelper DBHelper = new DataBaseHelper();

            //DBHelper.SQLExecuteNonQuery(procedure_name,command_parameters) return the object data.
            // casting return value to byte[]
            byte[] imageByte = (byte[])DBHelper.SQLExecuteNonQuery("sp_getImage", hash);
            //checking byte[] 
            if (imageByte != null && imageByte.Length > 0)
            {
                context.Response.ContentType = "image/jpeg";
                context.Response.BinaryWrite(imageByte);
            }
        }
    }

Example of Handler page displaying image, and check the URL, it display 3rd image from the Database.

Store procedure used to get Image

CREATE PROCEDURE sp_getImage
@imageID as numeric
AS
BEGIN
SELECT imageData FROM Images WHERE imageId=@imageID
END

I already said how to display image in Image Conrtol. now we can check how to display in GridView Control form folders and Database. From Database In the aspx page I put a GridView and , then set SqlDataSource, after that I add a Template column, then drag and drop a Image control in Template column and set ImageUrl of the image control using Image DataBinding Setting image url

Source of GridView Passing imageId to Handler.ashx page. It will display image as I said above.

Preview with HTML Source.

Displaying Image From Folder you need to add a template column in GridView after that put one image control on template column, then set image controls DataImageUrlField from DataTable.

<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="false">
     <Columns>
         <asp:ImageField  DataImageUrlField="Image">
         </asp:ImageField>
     </Columns>
 </asp:GridView>

Server side code

 private void BindImage()
    {
     
        DataTable dt = new DataTable();
        dt.Columns.Add(new DataColumn("Image", typeof(string)));
        DataRow dr;
        int i = 0;
  //fetching files from savedImages folder
        foreach (string file in Directory.GetFiles(Server.MapPath(@"savedImages\")))
        {
            dr = dt.NewRow();
            dt.Rows.Add(dr);
            dr["Image"] = "savedImages/" + System.IO.Path.GetFileName(file);
            i += 1;
        }
        GridView2.DataSource = dt;
        GridView2.DataBind();
    }

Now we can check how DataList works. Datalist is more simple control than GridView. Here aslo we call Database image with Generic Handler file Handler.ashx and pass "id" as QueryString. handler file display image, and we point that image in to our DataList Control.

<asp:DataList ID="DataList1" runat="server"
            RepeatColumns="3" RepeatDirection="Horizontal">
            <ItemTemplate>
                <table>
                    <tr>
                        <td valign="middle" align="center" style="background-color:#cccccc;border:1px solid gray;width:150px;height:150px;"><%#DataBinder.Eval(Container.DataItem, "images") %></td>
                    </tr>
                </table>
            </ItemTemplate>
        </asp:DataList>

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            BindDataList();
    }
    private void BindDataList()
    {
        string sqlCmd = "SELECT imageid FROM Images";
        DataBaseHelper DBHelper = new DataBaseHelper();
        DataTable dt = DBHelper.GetTable(sqlCmd);
        //adding new column to disply image
        DataColumn imageCol = new DataColumn("images", typeof(string));
        dt.Columns.Add(imageCol);
        
        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                dt.Rows[i][imageCol] = string.Format("<img src='Handler.ashx?id={0}' alt='' style='width:100px' />", dt.Rows[i][0].ToString());
            }
        }
        DataList1.DataSource = dt;
        DataList1.DataBind();
    }

Preview of Images in DataList Control

Creating Thumbnails image To create a thumbnail we need a image. we can pick image from FileUpload Control, then we need to know dimension of image ie [ Width x Height ]. Here I create a UI to handle this. check the UI

To maintain aspect ratio of image with height and width I use a class AspectRatio.cs you can get the source code "Browse Code" or "Download Source" Section. Now we can look the code of thumbnail creating section. As I said above here I call a function to create thumbs. let look at this. Below method returns Bitmap image, I am saving that image in root folder.

 public Bitmap CreateThumbnail(byte[] imageByte, bool maintainAspectRatio, int desiredWidth, int desiredHeight)
    {
        Bitmap bmp = null;
        try
        {
            MemoryStream memStream = new MemoryStream(imageByte);
            System.Drawing.Image img = System.Drawing.Image.FromStream(memStream);

            if (maintainAspectRatio)
            {
                AspectRatio aspectRatio = new AspectRatio();
                aspectRatio.WidthAndHeight(img.Width, img.Height, desiredWidth, desiredHeight);
                bmp = new Bitmap(img, aspectRatio.Width, aspectRatio.Height);
            }
            else
            {
                bmp = new Bitmap(img, desiredWidth, desiredHeight);
            }
            memStream.Dispose();
        }
        catch(Exception ex)
        {
            havException = true;
            ExceptionMessage = ex.Message;
        }
        return bmp;
    }

Server side code of "Create Thumbnail" Button. You can see this button in above image. here I pass image byte[] to CreateThumbnail Method. it return Bitmap Image. and save that file in root folder.

 protected void btnCreateThumb_Click(object sender, EventArgs e)
    {
        int width = 0;
        int height = 0;
        byte[] image = FileUpload1.FileBytes;
        Int32.TryParse(txtDWidth.Text, out width);
        Int32.TryParse(txtDHeight.Text, out height);
        ImageHandler imageHandler = new ImageHandler();
        bool maintainAR = cbxAspectRation.Checked;
        //calling CreateThumbnail Method to create thumb images
        //it returns Bitmap Image. 
        Bitmap bmp = imageHandler.CreateThumbnail(image, maintainAR, width, height);
        if (bmp != null)
        {
            //creating a file name with guid.
            string fileName = Guid.NewGuid().ToString() + ".jpg";
            //saving in current root folder.
            bmp.Save(Server.MapPath(fileName));
            //set image controls ImageUrl to saved Image, this is to view the thumbnail image
            Image1.ImageUrl = fileName;
        }
        else
        {
            //exception part
            if (imageHandler.havException)
            {
                Response.Write(imageHandler.ExceptionMessage);
            }
        }
    }

You can check preview of Thumbnail ,Height and Width of image with the help of Firebug console.

Creating Watermark Text on Image Now we can discuss how to add Watermark on image. I think you know about Watermark. here I call a method AddWatermarkText to add watermark on image. I pass image byte and watermark text to this method. method create on System.Drawing.Image object from MemoryStream. MemoryStream Hold the image Byte. using System.Drawing.SolidBrush and System.Drawing.Font we create Text after that

 
Graphics.DrawString(string s, Font font, Brush brush, PointF point);

we write text on Image. below method is AddWatermarkText(byte[] imageByte,string textOnImage); you can check that.

 

public Image AddWatermarkText(byte[] imageByte,string textOnImage)
    {
        System.Drawing.Image img = null;
        try
        {
            MemoryStream memStream = new MemoryStream(imageByte);
            img = System.Drawing.Image.FromStream(memStream);
            Graphics g = System.Drawing.Graphics.FromImage(img);
            Font font = new Font("Aril", 30, FontStyle.Bold);

            SolidBrush solidBrush = new SolidBrush(Color.Red);
            Point point = new Point(img.Width / 3, img.Height / 2);
            g.DrawString(textOnImage, font, solidBrush, point);
            g.Save();

            memStream.Dispose();
            g.Dispose();
            solidBrush.Dispose();
            font.Dispose();
        }
        catch(Exception ex)
        {
            havException = true;
            ExceptionMessage = ex.Message;
        }
        return img;
    }

above method return Image. I am saving this image in root folder and display it using a Image control. you can check the UI of add Watermark Page and watermark on resultant Image.

Now we can check the code of Add Watermark button

 protected void btnAddWaterMark_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            byte[] imgbyte = FileUpload1.FileBytes;
            //creating object of ImageHandler Class
            ImageHandler imageHandler = new ImageHandler();
            System.Drawing.Image imageWithWatermark = imageHandler.AddWatermarkText(imgbyte, txtWaterMarkText.Text);
            if (imageWithWatermark != null)
            {
                //file name to save
                string saveFileName = Guid.NewGuid().ToString() + ".jpg";
                //saving image in current root location
                imageWithWatermark.Save(Server.MapPath(saveFileName));
                //displaying image file in a Image Control
                Image1.ImageUrl = saveFileName;
                imageWithWatermark.Dispose();
            }
            else
            {
                if (imageHandler.havException)
                {
                    Response.Write(imageHandler.ExceptionMessage);
                }
            }
        }
    }

Image as Watermark In this section I am explaining how to add Image as watermark. I think you seen same website with images. they have their log on image. we can check how to do something link that first we need a logo image here I take codeproject's logo image to explain this example. I save CP logo image in watermarklogo folder.

I am embedding CP logo image in to an upload image, using Graphics.DrawImage(Image image, Point point); Method. here I add add fading to logo image using TextureBrush

 //add fading to logo image  using TextureBrush
        System.Drawing.Image waterMarkimage = System.Drawing.Image.FromFile(Server.MapPath("watermarklogo/CodeprojectLogo.jpg"));
        Graphics opacity = System.Drawing.Graphics.FromImage(waterMarkimage);
        Rectangle imageRect = new Rectangle(0, 0, waterMarkimage.Width, waterMarkimage.Height);
        Brush brush = new TextureBrush(waterMarkimage, imageRect);
        opacity.FillRectangle(brush, imageRect);
        opacity.Save();

check the sample image

Check the source code

protected void btnAddImageAsWaterMark_Click(object sender, EventArgs e)
    {
        byte[] imageByte = FileUpload1.FileBytes;
        MemoryStream memStream = new MemoryStream(imageByte);
        System.Drawing.Image img = System.Drawing.Image.FromStream(memStream);

        //add fading to logo image  using TextureBrush
        System.Drawing.Image waterMarkimage = System.Drawing.Image.FromFile(Server.MapPath("watermarklogo/CodeprojectLogo.jpg"));
        Graphics opacity = System.Drawing.Graphics.FromImage(waterMarkimage);
        Rectangle imageRect = new Rectangle(0, 0, waterMarkimage.Width, waterMarkimage.Height);
        Brush brush = new TextureBrush(waterMarkimage, imageRect);
        opacity.FillRectangle(brush, imageRect);
        opacity.Save();
       
        Graphics g = System.Drawing.Graphics.FromImage(img);
        Point point = new Point(img.Width / 3, img.Height / 2);
        g.DrawImage(waterMarkimage, point);
        string filename = Guid.NewGuid().ToString() + ".jpg";
        img.Save(Server.MapPath(filename));
        
        opacity.Dispose();
        memStream.Dispose();
        g.Dispose();
        waterMarkimage.Dispose();
        img.Dispose();

        Image1.ImageUrl = filename;
    }

Download full source code

Delete Data in GridView Using Template Button

noreply@blogger.com (Raju.M) — Mon, 20 Sep 2010 01:30:00 +0000

This article explain how to delete data from GridView using Template Buttons

Now we look how to add template button in GridView.
first select Edit Columns in GridView.

2nd add template column in GridView.

Now configuring template column, Click Edit Template. Place a LinkButton on Template field. Click Edit Databindings , then select CommandArgument , after that set field binding, bound to "ID" field, this ID field is used to delete data in server side code. Then press ok button.

Now we can configure LinkButton [ Delete button ].
Select Property of Link button. set CommandName and Text as Delete.
We can access this CommandName in GridView1_RowCommand event. After this add GridView events GridView1_RowCommand and GridView1_RowDeleted

The RowDeleted event is raised whenever a Delete button associated with an item in the GridView control is clicked, but after the GridView control deletes the record.

This allows you to provide an event-handling method that performs a custom routine, such as checking the results of a delete operation, whenever this event occurs. To avoid errors we add one custom code in GridView1_RowDeleted event

//handling gridview delete excetion
        e.ExceptionHandled = true;

Now the server side part.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void GridView1_RowDeleted(object sender, GridViewDeletedEventArgs e)
    {
        //handling gridview delete excetion
        e.ExceptionHandled = true;
    }
    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "dele")
        {
            //database Helper
            DBHelper objDBHelper = new DBHelper();
            //sql command to delete data from database
            string sqlCmdText = string.Format("DELETE FROM Table WHERE ID='{0}'", e.CommandArgument.ToString());
            //Executeing sql command
            objDBHelper.ExecuteScalar(sqlCmdText);
            //refresh gridview
            GridView1.DataBind();

        }
    }
}

ASPX Page

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            DataSourceID="SqlDataSource1" onrowcommand="GridView1_RowCommand"
            onrowdeleted="GridView1_RowDeleted">
            <Columns>
                <asp:BoundField DataField="biInvitationId" HeaderText="biInvitationId"
                    InsertVisible="False" ReadOnly="True" SortExpression="biInvitationId" />
                <asp:BoundField DataField="biEventName" HeaderText="biEventName"
                    SortExpression="biEventName" />
                <asp:BoundField DataField="biHostName" HeaderText="biHostName"
                    SortExpression="biHostName" />
                <asp:BoundField DataField="biTelephone" HeaderText="biTelephone"
                    SortExpression="biTelephone" />
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:LinkButton ID="LinkButton1" runat="server"
                            CommandArgument='<%# Eval("biInvitationId") %>' CommandName="dele">Delete</asp:LinkButton>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server">
        </asp:SqlDataSource>
    </div>
    </form>
</body>
</html>

Thank you,

Feel free to comment.

.

Select GridView Row without using Select button

noreply@blogger.com (Raju.M) — Sat, 04 Sep 2010 16:24:00 +0000

This code snippet Illustrate How to Select GridView Row without using Select Command button.
I think code can do better idea than description. check the snippet.

protected void Button1_Click(object sender, EventArgs e)
    {
        //identifying button
        Button gridBtn = (Button)sender;
       //selecting grid row
        GridViewRow gridRow = (GridViewRow)gridBtn.NamingContainer;
       //setting Index
        int selectedIndex = gridRow.DataItemIndex;
       // Setting Selected Index of GridView1
         GridView1.SelectedIndex = selectedIndex;
        //firing selected Index changed if you need
        //here I used to change color of selected rows
         GridView1_SelectedIndexChanged(GridView1, EventArgs.Empty);
        if (gridBtn != null)
        {
           //changing button text[/color]
            if (gridBtn.Text == "DeSelect")
            { gridBtn.Text = "Select"; }
            else
            { gridBtn.Text = "DeSelect"; }
        }

    }
    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        int sIndex = GridView1.SelectedIndex;
        if (GridView1.Rows[sIndex].BackColor == System.Drawing.Color.Red)
        {
            GridView1.Rows[sIndex].BackColor = System.Drawing.Color.White;
        }
        else
        {
            GridView1.Rows[sIndex].BackColor = System.Drawing.Color.Red;
        }

    }

ASPX section

I add One Button field as Template field. and add Button text as "Select". when you click on select button in GridView, the selected Row become Red color.

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            DataSourceID="SqlDataSource1">
            <columns>
                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                <asp:BoundField DataField="Category" HeaderText="Category"
                    SortExpression="Category" />
                <asp:BoundField DataField="Tags" HeaderText="Tags" SortExpression="Tags" />
                <asp:TemplateField>
                    <itemtemplate>
                        <asp:Button ID="Button1" runat="server" Text="Select" onclick="Button1_Click" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

Preview of Output
You can Select or Deselect GridView Rows.

Thank you for Reading this code snippet.
Feel Free to comment. if you have any doubts let me know.

Ajax AutoComplete in ASP.Net

noreply@blogger.com (Raju.M) — Thu, 02 Sep 2010 20:52:00 +0000

Without using AjaxControlToolKit we can implement AutoComplete Extender using pure Ajax Call. This article is explaining how to do make AutoComplete Extender.
OnKeyUp event help you to fetch data from Database with Ajax call. Here one Handler.ashx handles the AJAX request form Client. I add a Class file to handle database operations to better coding practice. Below I am explaining the database helper Class. Class have one method GetTable(string sqlQuery) this return DataTable after fetching data from database. And also include Provide Class, this Class help to get SqlConnection string.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;
/// 
/// Summary description for DBHelper
/// 
public class DBHelper
{
    SqlConnection connection;
    SqlDataAdapter adapter;
    SqlCommand command;
    DataTable dataTable;
    public DBHelper()
    {
    }
    /// 
    /// 
    /// 
    /// passing SQL Query here/// DataTable object is returned
    public DataTable GetTable(string sqlQuery)
    {
        //creating new instance of Datatable
        dataTable = new DataTable();
        connection = Provider.GetConnection();
        command = new SqlCommand(sqlQuery, connection);
        //Open SQL Connection
        connection.Open();
            try
            {
                adapter = new SqlDataAdapter(command);
                adapter.Fill(dataTable);
            }
            catch
            { }
            finally
            {
                //Closing Sql Connection 
                connection.Close();
            }
        return dataTable;
    }
}
public class Provider
{
    public static SqlConnection GetConnection()
    {
        //creating SqlConnection
        return new SqlConnection(ConfigurationManager.AppSettings["sqlConn"]);
    }
}

Now we can look into Handler file. When request come from Ajax Call from Client it passes the data into our Database helper Class, handler file hold the data in DataTable. Result data are formatted in a table and write in the context. We can add JavaScript function for select the data, here api_helper.AddtoTaxtBox(selectedItem)is managing client section of data. Check Handler file

<%@ WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
using System.Data;
public class Handler : IHttpHandler {
    public void ProcessRequest (HttpContext context) {

        HttpRequest request = HttpContext.Current.Request;
        //checking string null or empty
        if (!string.IsNullOrEmpty(request.QueryString["name"]))
        {
            string name=request.QueryString["name"];
            //creating instance of new database helper
            DBHelper objDBHelper = new DBHelper();
            //creating Sql Query
            string sqlQuery = string.Format("SELECT Name FROM User WHERE Name LIKE '{0}%'", name);
            //filling data from database
            DataTable dataTable = objDBHelper.GetTable(sqlQuery);

            string table = string.Empty;
            //table for hold data
            table = "";             string td = string.Empty;             //checking datatable                 if (dataTable.Rows.Count > 0)                 {                     for (int i = 0; i < dataTable.Rows.Count; i++)
                    {
                        //adding table rows
                        td += string.Format("
", dataTable.Rows[i][0].ToString());                     }                 }                 table += td + "{0}";
                context.Response.Write(table);
        }
    }
    public bool IsReusable {
        get {
            return false;
        }
    }

}

Now we can check how Ajax works. On Textbox onKeyUp event call the ajax code. It send the entered value into server using ajax and result displayed in div control under the search textbox.

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>

<style type="text/css">
      .select{cursor:pointer;height:20px;color:red;}
      .select:hover{cursor:pointer;height:20px;color:black;background-color:#cccccc;}
      #myDiv{position:relative;top: -1px; left: 0px;width:150px; overflow:hidden;}
      #txtName{width:150px}
</style>

</head>
<body>
<form id="form1" runat="server">
<div>

<asp:TextBox ID="txtName" runat="server" onkeyup="api_helper.callAjax();"></asp:TextBox>
<div id="myDiv"></div>


<script language="javascript" type="text/javascript">

            if (typeof (api_helper) == 'undefined') { api_helper = {} }


            api_helper.doAjax = function(HandlerUrl, displayDiv) {
                var Req; try { Req = new XMLHttpRequest(); } catch (e) { try { Req = new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) { return false; } } } Req.onreadystatechange = function() { if (Req.readyState == 4) { var d = document.getElementById(displayDiv); d.innerHTML = Req.responseText; } }
                Req.open("GET", HandlerUrl, true); Req.send(null);
            }


            api_helper.callAjax = function() {
                var text = document.getElementById("txtName").value;
                if (text != "") {
                    var requestUrl = "Handler.ashx?name=" + text;
                    var displayDiv="myDiv";
                    api_helper.doAjax(requestUrl, displayDiv);
                }
            }


            api_helper.AddtoTaxtBox = function(txt) {
                document.getElementById("txtName").value = txt;
                document.getElementById("myDiv").innerHTML = "";
            }
</script>
</div>
</form>
</body>
</html>

Thanks for reading this article and feel free to comment.
Tags Ajax AutoComplete, Ajax Example.

UpdateProgress Control

noreply@blogger.com (Raju.M) — Thu, 08 Jul 2010 15:23:00 +0000

This sample illustrate how to implement UpdateProgress Control in ASP.Net

UpdatePanel control enable partial page rendering in ASP.Net. using UpdateProgress control enable status when Updating UpdatePanel. UpdateProgress have ProgressTemplate, When updates is happen UpdateProgress show the content in ProgressTemplate.

  <asp:UpdateProgress ID="UpdateProgress1" AssociatedUpdatePanelID="UpdatePanel1" runat="server">
            <ProgressTemplate>
                <div style="color:Red;font-size:xx-large;">Please wait ......</div>
            </ProgressTemplate>
       </asp:UpdateProgress>

AssociatedUpdatePanelID is enable which update is shown update process. Here i am displaying time in label control. When user click update button status is shown in UpdateProgress control

protected void UpdateTime_Click(object sender, EventArgs e)
    {
         //sleeps for 2 seconds 
        System.Threading.Thread.Sleep(2000);
        lblDate.Text = DateTime.Now.ToString();
    }

Full Source Code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
               <asp:ScriptManager ID="ScriptManager1" runat="server">
               </asp:ScriptManager>
               
               <asp:UpdateProgress ID="UpdateProgress1" AssociatedUpdatePanelID="UpdatePanel1" runat="server">
                    <ProgressTemplate>
                        <div style="color:Red;font-size:xx-large;">Please wait ......</div>
                    </ProgressTemplate>
               </asp:UpdateProgress>
                
                <asp:UpdatePanel runat="Server" ID="UpdatePanel1" UpdateMode="Conditional">
                            <ContentTemplate>
                                <asp:Label ID="lblDate" runat="server"></asp:Label>
                                <asp:Button ID="UpdateTime" runat="server" onclick="UpdateTime_Click" Text="Update" />
                            </ContentTemplate>
                </asp:UpdatePanel>
         </div>
    </form>
</body>
</html>

Server side code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Reflection;
public partial class Default2 : System.Web.UI.Page
{
    
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            lblDate.Text = DateTime.Now.ToString();
        }
       
    }
    protected void UpdateTime_Click(object sender, EventArgs e)
    {
        //sleeps for 2 seconds 
        System.Threading.Thread.Sleep(2000);
        lblDate.Text = DateTime.Now.ToString();
    }
}

Output

Download Source

How to get Session Variable in Class File

noreply@blogger.com (Raju.M) — Wed, 07 Jul 2010 23:24:00 +0000

How to get Session Variable in Class (.cs) File

Normally Session is not accessible in Class file. when one try to call Session in class file it return "Object reference not set to an instance of an object." error description like " An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code." this error is thrown by System.NullReferenceException. To access Session in class file Microsoft introduce a Interface IRequiresSessionState, derived from System.Web.SessionState

The metadata of IRequiresSessionState

namespace System.Web.SessionState
{
    // Summary:
    //     Specifies that the target HTTP handler requires read and write access to
    //     session-state values. This is a marker interface and has no methods.
    public interface IRequiresSessionState
    {
    }
}

IRequiresSessionState Specifies that the target HTTP handler requires read and write access to session-state values. IRequiresSessionState has no methods.

How to Use

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.SessionState;
/// 
/// Summary description for GetSessionHelper
/// 
public class SessionHelper : IRequiresSessionState
{
    public SessionHelper()
    {
        //
        // TODO: Add constructor logic here
        //
    }
    /// 
    /// Get Session values
    /// 
    /// session key    /// object value
    public object GetSession(string key)
    {
        //check session 
        if (HttpContext.Current.Session[key] != null)
        {
            //return session value
            return HttpContext.Current.Session[key];
        }
        else
        {
            //return empty string
            return string.Empty;
        }
    }
}

Calling SessionHelper Class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //Creating object of SessionHelper Class
        SessionHelper objSessionHelper = new SessionHelper();
        //setting session value in a variable
        string sessionValue = objSessionHelper.GetSession("test").ToString();
        //writing session value in Page
        Response.Write(sessionValue);
    }
}

Get Value of Dynamically generated TextBox

noreply@blogger.com (Raju.M) — Tue, 06 Jul 2010 05:07:00 +0000

how to get value of dynamically generated TextBox using javascript

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
public partial class placeholderissue : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            if (TextBox1.Text != string.Empty)
            {
                int count = 0;
                int.TryParse(TextBox1.Text, out count);
                
                for (int i = 0; i < count; i++)
                {
                    TextBox txt = new TextBox();
                    txt.ID = "dynamicText" + i.ToString();
                    if (PlaceHolder1.FindControl(txt.ID) != null)
                    {
                        PlaceHolder1.Controls.Add(txt);
                    }
                }
            }
        }
      
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        if (TextBox1.Text != string.Empty)
        {
            int count=0;
            int.TryParse(TextBox1.Text,out count);
            for (int i = 0; i < count; i++)
            {
                TextBox txt = new TextBox();
                txt.ID = "dynamicText" + i.ToString();
                PlaceHolder1.Controls.Add(txt);
            }
        }
    }
}

HTML

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="placeholderissue.aspx.cs" Inherits="placeholderissue" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <asp:Button ID="Button1"
            runat="server" Text="Button" onclick="Button1_Click" />
        <br />
        <asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
        <input id="Button2" type="button" value="button" onclick="GetTextBoxValue();" />
        <script language="javascript">
            function GetTextBoxValue() {
                var count = document.getElementById("TextBox1").value;
                if (count > 0) {
                    for (i = 0; i < count; i++) {
                        alert(document.getElementById("dynamicText" + i).value);
                    }
                }
            }
        </script>
    <div>
    </form>
</body>
</html>

Source Code

Insert Image in to Database

noreply@blogger.com (Raju.M) — Tue, 06 Jul 2010 02:40:00 +0000

Insert Image in to Database

datatype of image in database is Byte[], so we insert image byte in to Database

FileUploader controls is used to select file, FileUploader control have a property FileBytes it return byte array (byte[]) of image, this Byte[] is stored in dataBase

example


 using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Text;
using System.Data.SqlClient;
public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
       
    }
    protected void ImageUploadToDataBase(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection("Your Connection string");
        try
        {
            con.Open();
            byte[] imageByte = FileUpload1.FileBytes;
            SqlCommand cmd = new SqlCommand("INSERT INTO table (image,imagename) VALUES (@0,@1))", con);
            object[] cmdParams = new object[2];
            cmdParams[0] = imageByte;
            cmdParams[1] = "Name of Image";
            for (int i = 0; i < cmdParams.Length; i++)
            {
                cmd.Parameters.AddWithValue(i.ToString(), cmdParams[i]);
            }
            cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
        }
        finally { con.Close(); }
       
    }
    
}