Kenny Hsu's Blog

SQL get current datetime

2012-02-08T02:03:00.000-06:00

SELECT CURRENT_TIMESTAMP

SELECT {fn NOW()}

SELECT GETDATE()

byte[] convert to hexadecimal string (and vice versa)

2012-02-07T22:00:00.000-06:00

byte[] to hex string:

static string ByteArrayToString1(byte[] source)
{
    StringBuilder sb = new StringBuilder();
    foreach (byte item in source)
    {
        sb.AppendFormat("{0:x2}", item);
    }
    return sb.ToString();
}

static string ByteArrayToString2(byte[] source)
{
    return BitConverter.ToString(source).Replace("-", "");
}

static string ByteArrayToString3(byte[] source)
{
    // namespace: System.Runtime.Remoting.Metadata.W3cXsd2001
    return new SoapHexBinary(source).ToString();
}

static string ByteArrayToString4(byte[] source)
{
    // works for .Net 4 only
    return String.Concat(Array.ConvertAll(source, x => x.ToString("X2")));
}

Loop through enum

2012-02-07T19:19:00.000-06:00

enum Week
{
    Sunday,
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday
}

foreach (Week item in Enum.GetValues(typeof(Week)))
{
    //...
}

Reference: Can You Loop Through All Enum Values? c#

IPv4 Address convert to Integer (and reverse) (updated)

2012-01-16T20:04:00.000-06:00

static Int64 IPv4StringToInt64(string ipv4String)
{
    Int64 ipInteger = 0;
    try
    {
        ipInteger = (long)(uint)IPAddress.NetworkToHostOrder(BitConverter.ToInt32(IPAddress.Parse(ipv4String).GetAddressBytes(), 0));
    }
    catch (Exception)
    { }

    return ipInteger;
}

static string IPv4Int64ToString(Int64 ipv4Int64)
{
    if (ipv4Int64 < 0)
        return "0.0.0.0";
    else if (ipv4Int64 < 4294967295)
        return IPAddress.Parse(ipv4Int64.ToString()).ToString();
    else
       return "255.255.255.255";
}

Usage:

Console.WriteLine("255.255.255.0 => " + IPv4StringToInt64("255.255.255.0"));
Console.WriteLine("4294967040 => " + IPv4Int64ToString(4294967040));

Reference: stackoverflow - How to convert an IPv4 address into a integer in C#?

Kenny's XML Encrypter

2011-06-19T20:08:00.000-05:00

Name: Kenny's XML Encrypter
Version: 1.1
Platform: Windows with .Net Framework 2.0 installed
Introduction:
A small tool that can encrypt/decrypt xml element and attribute value. You can click Help button to see how to use it.
You can set different keys to encrypt different elements or attributes in the same time. Just don't forget those keys.
This tool only works on those leaf elements.
Play around, and leave a message at here if you found any problems.

PS: Don't forget to keep an original copy of your XML file in case something happeded. The save is done automatically when you click the "Encrypt" or "Decrypt" button.

Refresh WebBrowser in Winform

2011-06-14T00:25:00.001-05:00

I put a WebBrowser control on my form and use it to load XML files. Here is the code:

OpenFileDialog FileDialog = new OpenFileDialog();
FileDialog.Title = "Open XML Document";
FileDialog.Filter = "XML file (*.xml)|*.xml";
if (FileDialog.ShowDialog() == DialogResult.OK)
{
  WebBrowser1.Navigate(FileDialog.FileName);
  WebBrowser1.Refresh();
}

I found that if I load the second XML, sometimes it will not refresh itself to show the new XML content. Instead, it still shows the previous one. I google the web to see if there is any other way to prevent the cache. Unfortunately, I found nothing. But this post inspires me and so I create a workaround.
Read more »

Integrated the EasyAlgo FlashUpload control into the ASP.Net web application

2011-05-24T00:51:00.000-05:00

Recently, I used their FlashUpload flash control to manage user uploads. It is a very powerful flash control that can let you customize the control. The price is affordabile (or you can try it free without limitations), and their customer service is outstanding. I use google talk to chat with them when I encounter any problem (also request some features!) with no problem.

OK, no more advertisement. :) Below is an example of what I've done for customizing it. The reason I put a blog here is because their document is good but not organized very well. I spent lots of time on puting things together... You can select many ways to integrate the flash control into your web app. Here I choose javascript.
Read more »

[javascript] Text wrapping in the alert/confirm function

2011-03-03T22:31:00.001-06:00

Wrap words in the javascript alert (or confirm).

This doesn't work.
alert("First Line<br/>Second Line")

This doesn't work.

alert("First Line\r\nSecond Line")

This will work

alert("First Line\\r\\nSecond Line")

Simple file upload by using FileUpload control.

2011-02-25T17:01:00.014-06:00

What I need:
1.User can upload only one file at a time.
2.No save file to disk; read it's content and then dispose it.
3.Only txt and csv file types are allowed.

Here is the aspx page

<asp:Panel ID="PanelUploadList" runat="server" ViewStateMode="Disabled">
    <hr />
    Please select a text file to upload:
    <asp:FileUpload ID="FileUpload1" runat="server" />
    <asp:RequiredFieldValidator ID="RequiredFieldValidatorFileUpload" runat="server"
        ControlToValidate="FileUpload1"
        ErrorMessage="Please select a file to upload!" Display="Dynamic">*asp:RequiredFieldValidator>
    <asp:RegularExpressionValidator ID="RegularExpressionValidatorFileUpload" runat="server"
        ControlToValidate="FileUpload1" ValidationExpression="^(([a-zA-Z]:)|(\\{2}\w+)\$?)(\\(\w[\w].*))+(.txt|.csv)$"
        ErrorMessage="Only txt and csv file types are allowed!">*asp:RegularExpressionValidator>
    <asp:Button ID="ButtonUpload" runat="server" OnClick="ButtonUpload_Click"
        Text="Upload" />
    <hr />
</asp:Panel>

Sort ListBox items (ascending/descending)

2011-01-20T17:42:00.002-06:00

1. Create a class that implements IComparer<T> interface.

private class SortListItem : IComparer<ListItem>
{
    public int Compare(ListItem x, ListItem y)
    {
        return String.Compare(x.Value, y.Value);
    }
}

DateTime: Get the first date of the week

2011-01-20T13:32:00.000-06:00

1. Create an extension method.

public static class DateTimeExtensions
{
    public static DateTime StartOfWeek(this DateTime dt, DayOfWeek startOfWeek)
    {
        int diff = dt.DayOfWeek - startOfWeek;
        if (diff < 0)
        {
            diff += 7;
        }

        return dt.AddDays(-1 * diff).Date;
    }
}

Enum - simple example

2011-01-20T13:15:00.002-06:00

class Program
{
    enum DateTypeEnum
    {
        Year = 1,
        Quarter = 2,
        Month = 4,
        Day = 8
    }

    static void Main(string[] args)
    {
        int AvailablePayMethod = 7;

        Console.WriteLine("Your available Paying Methods are: ");

        //check all available paying methods
        if ((AvailablePayMethod & (int)DateTypeEnum.Year) == (int)DateTypeEnum.Year)
            Console.WriteLine(DateTypeEnum.Year);

        if ((AvailablePayMethod & (int)DateTypeEnum.Quarter) == (int)DateTypeEnum.Quarter)
            Console.WriteLine(DateTypeEnum.Quarter);

        if ((AvailablePayMethod & (int)DateTypeEnum.Month) == (int)DateTypeEnum.Month)
            Console.WriteLine(DateTypeEnum.Month);

        if ((AvailablePayMethod & (int)DateTypeEnum.Day) == (int)DateTypeEnum.Day)
            Console.WriteLine(DateTypeEnum.Day);

        Console.WriteLine();

        int FavoritePayMethod = 4;

        //retrieve enum
        DateTypeEnum BillPeriod = (DateTypeEnum)Enum.Parse(typeof(DateTypeEnum), FavoritePayMethod.ToString());
        Console.WriteLine("Your Favorite Paying Method is \"{0}\".", BillPeriod);
    }
}

Doing some works after Response.End()

2010-12-17T13:32:00.004-06:00

I need to do something that after users download a file from my website. Most file downloading approach is using something like this:

//data preparation at here...

Page.Response.ClearContent();
Page.Response.ClearHeaders();
Page.Response.Clear();
Page.Response.Buffer = true;
Page.Response.ExpiresAbsolute = DateTime.Now.Subtract(new TimeSpan(1, 0, 0, 0, 0));
Page.Response.Expires = 0;
Response.AddHeader("content-disposition", "attachment;filename=" + YourFileNameHere + ".xls";
//here I use excel file type
Response.ContentType = "application/vnd.ms-excel";
//FileContent is a string variable which stores your file content
Page.Response.AddHeader("content-length", FileContent.Length.ToString());
Response.Write(FileContent);
Response.End();

Mobile version is on.

2010-12-16T12:02:00.000-06:00

Added a mobile version to my blog. If you use your smart phone to browse my blog, it will transfer you to the mobile version of my blog after few seconds.

Tips: Prevent CheckBox from being changed by user

2010-12-03T10:07:00.004-06:00

The easiest way to prevent your CheckBox from being changed by users is adding this to your CheckBox's html code:

OnClick="return false;"

For example:

<asp:CheckBox ID="CheckBox1" runat="server" Text="Want a salary increase?" Checked="False"
 OnClick="return false;" />

How to copy codes in my blog

2010-11-23T11:36:00.000-06:00

Since I am using the latest syntex highlighter, there is no more flash control for users to copy the code or view code in text mode.

The new way to copy the code is "double click" on the code and it will mark all codes automatically. Then press "Ctrl + C" will do the work.

SqlDataSource/ObjectDataSource use ViewState

2010-11-16T11:22:00.000-06:00

On SqlDataSource's Selecting event:

protected void SqlDataSource1_Selecting(object sender, SqlDataSourceSelectingEventArgs e)
{
    e.Command.Parameters["UserID"].Value = ViewState["UserID"].ToString();
}

On ObjectDataSource's Selecting event:

protected void ObjectDataSource1_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
{
    e.InputParameters["UserID"] = ViewState["UserID"].ToString();
}

SyntaxHighlighter broken

2010-11-11T14:40:00.000-06:00

My SyntaxHighlighter is broken so those codes looks ugly... I will fix it (hopefully soon enough).

Two DateTime related questions and solutions.

2010-11-11T14:22:00.007-06:00

How do I get the month name?
1.

DateTime.Now.ToString("MMMM")

CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(DateTime.Now.Month)

If you want to use the method 2, don't forget to include the

using System.Globalization;

How to know this Sunday's date? (or Monday, Tuesday... etc)
First, create an extension method.

public static class DateTimeExtensions
{
  public static DateTime StartOfWeek(this DateTime dt, DayOfWeek startOfWeek)
  {
    int diff = dt.DayOfWeek - startOfWeek;
    if (diff < 0)
    {
      diff += 7;
    }

    return dt.AddDays(-1 * diff).Date;
  }
}

Then call it like this

DateTime.Now.StartOfWeek(DayOfWeek.Sunday)

so that I can get the date of this week's Sunday.

I have these two questions is because I am creating a Google Calendar-liked calendar . :)

Reference:
Month Name in C#
How can I get the DateTime for the Start of the Week

Aspx page, Frameset, and QueryString

2010-10-21T19:39:00.008-05:00

I encountered a situation that I have to pass values through the query string to an aspx page which contains frameset settings. Here is what I found how to do it (and it works for me).

Let's say I have a Default.aspx which has a frameset settings, and it contains two frames link to Menu.aspx and Content.aspx. Here is the html code for the Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="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>xxxx</title>
 </head>
 <frameset cols="20%,80%">
  <frame name="Menu" src=<%= GetMenuFrame()%> />
  <frame name="Content" src=<%= GetContentFrame()%> />
 </frameset>
</html>

Distinct in DataTable or DataView

2010-07-07T22:08:00.009-05:00

How to remove duplicated data? Suppose I have a DataTable (dtMembers) looks like this:

ID	Name	City	ZipCode
01	Kenny	LA	12345
02	Peter	CA	54321
03	John	NY	13125
04	Jimmy	NY	13125

Using the following two lines of codes if you want to get the non-duplicated city list:

string[] columnNames = new string[] { "City" };
DataTable dtCity = dtMembers.DefaultView.ToTable(true, columnNames);

The result will be "LA, CA, NY".

Take a look of the DataView.ToTable() method and this discussion.

[SSRS 2005] One table uses two DataSets by using Multivalue Parameter

2010-04-21T13:46:00.019-05:00

It's not possible that one report item (table, matrix, list... etc) can use two different datasets. Most people will suggest you to merge them into one dataset, but that doesn't work for me because they are not from the same database.

In my case, one dataset is coming from SQL 2005, and another one is coming from OSIsoft PI Server. I want to create a table that display hourly data for each day by using these two datasets. Not only so, some data are calculated on the fly by refering them. It's like mission impossible to create a report like this: these two datasets don't know each other, and one table cannot be assigned two datasets.

Here is how I solved this problem. Read more »

Get .Net Color from Hex Color (Hex string)

2010-04-05T11:24:00.004-05:00

It's easy but also easy to forget. I put it here as a note for myself. :)

Label1.BackColor = System.Drawing.ColorTranslator.FromHtml("#FFC0FF");

[ASP.NET]The DataSourceMode of SqlDataSource

2010-03-25T15:50:00.006-05:00

By default, the DataSourceMode of the SqlDataSource is DataSet. Here is how to retrieve the dataset from the SqlDataSource control:

DataTable dt = ((DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty)).ToTable();
or
DataTable dt = ((DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty)).Table;

If you set the DataSourceMode to DataReader, here is how to read the data:

IDataReader reader = (IDataReader)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
while (reader.Read())
{
//your code here
}
reader.Close();
reader.Dispose();

[ASP.Net]Dynamically assign your page's background image

2009-12-11T14:31:00.007-06:00

I would like to change/assign a page's background image depends on some conditions, and here is what I did.
1.Assign an id to the body and add the runat="server" to it.

2.Add the following code to your code-behind (you can put it in the Page_Load event)

if (ConfigurationManager.ConnectionStrings["MyWebsite"].ConnectionString.Contains("test"))
    body1.Style.Add("background-image", @"url(Images/test.jpg)");
else
    body1.Style.Add("background-image", @"url(Images/production.jpg)");

Modify the if statement to meet your needs.