Makai Studio

How to Set a default image for an ASP.Net image control

contact@makaistudio.com — Thu, 24 Jun 2010 12:42:00 PDT

I came across this problem today when trying to set the default image of an ASP.net image control. There is an option to set the alternate text but its not going to work, all this option does is to set a big red X. By doing some search on Bing I found a solution, the solution offered will work if you are using the code behind feature, if not, adding a script tag in the aspx page will create an error. here is the solution that was provided and then the solution I came up with when not using code behind,

Using code behind:

First add the javascript in your <head> tag

<script type="text/javascript>

  

function Defaultimage(img)

  

{

img.src(Defaultimage.jpg)

}

  

</script>

add onerror attribute to your image control:

Note: The onerror attribute is not a standard attribute of the image control, but once rendered into HTML it will work just fine.

<asp:Image ID="lblPhoto" runat="server" BorderStyle="Solid" BorderWidth="3px" onerror="DisplayDefaultImage(this)"

BorderColor="#dcdcdc" ImageUrl="myimage.jpg"/>

When not using code behind

add a scriptManager control to your page then set the path to your Javascript file.

<asp:ScriptManager ID="ScriptManager1" runat="server">

    <Scripts>

   <asp:ScriptReference Path="~/directory/DisplayDefaultImage.js" />

   </Scripts>

    </asp:ScriptManager>

add onerror attribute to your image control:

<asp:Image ID="lblPhoto" runat="server" BorderStyle="Solid" BorderWidth="3px" onerror="DisplayDefaultImage(this)"

BorderColor="#dcdcdc" ImageUrl="myimage.jpg"/>

ASP.NET Concatenating string value

contact@makaistudio.com — Wed, 21 Jul 2010 18:54:00 PDT

Problem:

Trying to concatenate user Last name, first name and Middle name in an Hyperlink control using inline binding.

Solution:

Use the String.Format

<asp:HyperLink ID="HyperLink1"  NavigateUrl='

<%#String.Format("Default.aspx?assignment={0}",Eval("dispname")) %>'  runat="server">

<%# String.Format("{0} {1} {2}", Eval("lastname"), Eval("firstname"), Eval("midinitial"))%>

</asp:HyperLink>

ASP.Net How to loop through a ChecklBoxList control in C#

contact@makaistudio.com — Wed, 04 Aug 2010 00:16:00 PDT

string msg = "";

        string selectionResult = "";

        foreach (ListItem li in CheckBoxList1.Items)

            if (li.Selected == true)

                msg += "<br>" + li.Text;

            selectionResult = msg;

ASP.Net Validating for Max Number of Characters in a TextBox. C# Sample

contact@makaistudio.com — Wed, 01 Sep 2010 19:51:25 PDT

Let's say you have a Text Box = TextBox1 (textMode=MultiLine etc...) and you want to validate/Limit the number of character entered by a user

Do this:

Add a customField Validator.
In the customValidator properties: ErrorMessage = "Your Error Message" ControlToValidate ="control you want to validate"
Select the Event button or double click the CustomValidator on the page.
In the code behind Enter the following:

protected void CustomValidator1_ServerValidate
(object source, ServerValidateEventArgs args)

        if (TextBox1.Text.Length > 10)

            args.IsValid = false;

        else

            args.IsValid = true;

To avoid making a trip to the server and have instant validation when tabbing or moving to another field do this.

Return to the CustomValidator control properties and add under Behavior:
ClientValidationFunction = validateComments (or whatever text you want to call it)
In your aspx file add a ScriptManager from the Ajax Extensions.
Then add a new Item and select JScript File
In the script file add the following function.

Voila! if you using a master page add the SciptManager in your master page. Hope this helped.

function validateComments(sender, args)

    if (args.Value.length > 10)

        args.IsValid = false;

    else

        args.IsValid = true;

Also, Reference the file in your script manager(see below after the function).

<asp:ScriptManager ID="ScriptManager1" runat="server">

    <Scripts>

    <asp:ScriptReference Path="~/validateComments.js" />

    </Scripts>

    </asp:ScriptManager>

Getting the IP address of server in ASP.Net and C#

contact@makaistudio.com — Fri, 03 Sep 2010 02:18:21 PDT

Drop a label in your aspx page.

in code behind:

   1: string strHostName = System.Net.Dns.GetHostName();

   2:      IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());

   3:      IPAddress ipAddress = ipHostInfo.AddressList[0];

   4: label1.Text = Convert.toString(ipAddress);

If you have any question, shoot me an email

Retrieve and display Data from an Excel file using ADO.net. C# example

contact@makaistudio.com — Tue, 23 Nov 2010 18:19:00 PST

In this tutorial, I will retrieve data from an Excel file using ADO.net, then display the data into a Gridview.
1. Start by creating your Excel file.

2. Save the file as Employees.xls (Excel 97/2003 XLS Workbook) or Employees.xlsx (Excel 2007 xlsx.) I will show you both connection string.

3. Save the file in the root directory of your site (I will recommend to save this in the App_data folder for commercial use, because this folder can not be browsed)

1: string connString = @"Provider=Microsoft.Jet.OLEDB.4.0;" +

   2:"Data Source=" + Server.MapPath("Employees.xls") + ";" +

   3: "Extended Properties=Excel 8.0;";

Connection string for Excel 2007 : "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Employees.xlsx;Extended Properties=Excel 12.0"/> replace accordingly

Note: Server.MapPath maps the specified relative or virtual path to the corresponding physical directory on the server.

Here is the full code

Imports System.Data
Imports System.Data.OleDb

protected void Page_Load(object sender, EventArgs e)
    {

             string connString = @"Provider=Microsoft.Jet.OLEDB.4.0;" +
            "Data Source=" + Server.MapPath("../App_data/Employees.xls") + ";" +
            "Extended Properties=Excel 8.0;";


        //Create Connection
        OleDbConnection oledbbConn = new OleDbConnection(connString);
        try
        {
            

            // Create OleDbCommand object and select data from worksheet Sheet1

            OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet1$]", oledbbConn);

            // Create new OleDbDataAdapter as an intermediary
            //between the database and the Dataset itself need to be setup first
            OleDbDataAdapter oleda = new OleDbDataAdapter();
            oleda.SelectCommand = cmd;

            //Open Connection
            oledbbConn.Open();

            // Create a DataSet which will hold the data extracted from the worksheet.
            DataSet ds = new DataSet();

            // Fill the DataSet from the data extracted from the worksheet.
            oleda.Fill(ds, "Employees");

            // Bind the data to the GridView
            GridView1.DataSource = ds.Tables[0].DefaultView;
            GridView1.DataBind();

           
        }
        catch (Exception error)
        {
            Label1.Text = "The following Error has occurred" + error.Message;
        }
        finally
        {
            //Close the connection
            oledbbConn.Close();
        }

Notes:
Sheet1$ refer to the name of the Sheet in your Excel Workbook (without the $ sign) containing the data. It can be any name,just make sure that the name of the worksheet is followed by the dollar sign ($) when specifying in the query. If the dollar sign is not included you will get an error.

Query: To return all employees with location = Los Angeles:
OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet1$]WHERE [Firm Company Name]='Los Angeles'", oledbbConn);

In this example I am binding to a GridView. You can also bind to a repeater. Something like this:

<asp:ListView….

<itemTemplate>

<li><b>Completed Date: </b><%#DataBinder.Eval(Container.DataItem, "Completed Date")%></li>

</itemTemplate>

Warning: if your site is hosted on a windows 2008 64 bit server, you will get the following error when deploying your application:

Error: The following Error has occurred. The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine.

Reason: Microsoft never designed OLE drivers for 64 bit use

Solution: Ask your hosting company to change the application pool to 32 bit mode.

If you have any question, please feel free to shoot me an email.

SQL Unlock Reset Enable sa account

contact@makaistudio.com — Fri, 04 Mar 2011 01:27:00 PST

//Check if the account is Enabled
C:\Users\delpayjadm>osql -U sa -S LAWEBDEV02\SQLEXPRESS
Password: <Enter password>

You get this? "Login failed for user 'sa'. Reason: The account is disabled.

//To Enable sa account that has been Disabled
C:\Users\delpayjadm>sqlcmd -S LAWEBDEV02\SQLEXPRESS
1> ALTER LOGIN sa ENABLE
2> go
1>

//Unlock Password
C:\Users\delpayjadm>sqlcmd -S LAWEBDEV02\SQLEXPRESS
1> ALTER LOGIN sa WITH PASSWORD ='<newpassword>' UNLOCK
2> go

You get this? Msg 15118, Level 16, State 1, Server LAWEBDEV02\SQLEXPRESS, Line 1
Password validation failed. The password does not meet Windows policy requirements because it is not complex enough.

Solution: password must contains number + letter + special character

ASP.Net How to Format a Date in a GridView programmatically

contact@makaistudio.com — Wed, 02 Nov 2011 19:58:00 PDT

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)

{ if (e.Row.RowType == DataControlRowType.DataRow)
    {
        e.Row.Cells[5].Text = DateTime.Parse(e.Row.Cells[5].Text).ToString("MM/dd/yyyy");

    }
    }

Voila!!

How to retrieve value from a checkbox list C# sample

contact@makaistudio.com — Tue, 08 Nov 2011 18:54:00 PST

// Get Values from CheckBoxList
String values = "";
for (int i=0; i< cbl.Items.Count; i++)
{
        if(cbl.Items[i].Selected)
        {
                values += cbl.Items[i].Value + ",";
        }
}

values = values.TrimEnd(',');

How to set default value on DropDownList bound with Data Source

contact@makaistudio.com — Fri, 11 Nov 2011 01:47:00 PST

Add the following code to the OnDatabound event (OnDataBound="helperName_Databound")

protected void voidhelperName_Databound(object sender, EventArgs e)

{helperName.Items.Insert(0,

new ListItem("---Select From The List---"));}