Kenny Hsu's Blog

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

2009-12-11T14:31:00.005-06:00

I would like to change/assign a page's background image depends on some conditions, and here is they way I do.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/

[C# 2.0] Get and Check Daylight Saving Time (DST)

2009-12-02T09:25:00.009-06:00

Here is the way to get the DST:using System.Globalization;public static DataTable GenerateDST(int startYear, int endYear){ DataTable dt = new DataTable(); //get the current timezone TimeZone oTimeZone = TimeZone.CurrentTimeZone; DaylightTime oDST; dt.Columns.Add("Year"); dt.Columns.Add("Start Date"); dt.Columns.Add("End Date"); for (int i = startYear; i <= endYear; i++)

[C#]My simple version of Captcha

2009-11-09T09:54:00.005-06:00

This is my own version of Captcha. It's easy and simple. You can improve it with your ideas or needs.using (Bitmap bmp = new Bitmap(90, 30)){ int x1 = 0; int y1 = 0; int x2 = 0; int y2 = 0; int x3 = 0; int y3 = 0; int intNoiseWidth = 25; int intNoiseHeight = 15; Random rdn = new Random(); Graphics g = Graphics.FromImage(bmp); //set the font style Font font =

[C#][WinForm]Prevent same process to be executed more than once at the same time: a simple approach

2009-11-05T11:31:00.004-06:00

This is a simple and easy way to do it if your requirement is simple. Otherwise you should use Mutex.using System.Diagnostics;private void Form1_Load(object sender, EventArgs e){ try { string strModuleName = Process.GetCurrentProcess().MainModule.ModuleName; string strProcessName = Path.GetFileNameWithoutExtension(strModuleName); Process[] aryProcess =

[C#]Simple windows registry manipulation

2009-10-19T22:46:00.004-05:00

using Microsoft.Win32;//Attempt to open the key.RegistryKey key = Registry.CurrentUser.OpenSubKey(@"Software\Play\WindowPosition");//The key doesn't exist if it returns null.if (key == null){ //Create & open it. key = Registry.CurrentUser.CreateSubKey(@"Software\Play\WindowPos"); key.SetValue("PositionX", Location.X); key.SetValue("PositionY", Location.Y);}else{ //Get value

GetWords

2009-10-18T16:27:00.006-05:00

Name: GetWordsVersion: 1.3Platform: Windows with .Net Framework 2.0 installedIntroduction:Fetch words from the given article. It will fetch, sort, remove duplicated words. It will ignore the word that less than 3 characters like am, is, as... etc.How to use:1.Paste anything you want to parse on the left-hand side textbox.2.Click the "Get Words!" button, and the result will show on the right-hand

KB: You must call the Bind method before performing this operation.

2009-10-07T09:27:00.007-05:00

I got this error message: "You must call the Bind method before performing this operation." when using the UDP protocol to communicate with another application. Here is the simplified code.......IPAddress serverIP = IPAddress.Parse("xx.xx.xx.xx");IPEndPoint serverEP = new IPEndPoint(serverIP, 12345);UdpClient client = new UdpClient();//start listeningclient.BeginReceive(new AsyncCallback(

[C#][Winform]Show Confirm window

2009-10-06T14:32:00.002-05:00

In ASP.Net you can popup a confirm window easily. See this and this. How to do the same thing in windows form? Here is the easiliest way I know:if (MessageBox.Show("Are you sure you want to delete it?","Confirm", MessageBoxButtons.YesNo) == DialogResult.Yes){ //......}

I Am Busy! 1.0

2009-09-16T14:02:00.010-05:00

Name: I Am Busy!Version: 1.0OS: Windows with .Net Framework 2.0 installed.Introduction:Want to take a break with an excuse? :)How to use:Just click on the "OK" button once you set the title, showing message, total running time and refresh interval (or run it with the default value). You can take a break then.The program will close automatically after the given time is reached.

[Winform] Set ComboBox's value by the given value

2009-08-27T09:31:00.004-05:00

Here is the same purpose of the DropDownList control. Here is the same thing for the winform ComboBox control.internal static void SetDropDownByText(ComboBox cbox, string text){ if (cbox != null) { DataTable dt = (DataTable)cbox.DataSource; for (int i = 0; i < dt.Rows.Count; i++) { if ((string)dt.Rows[i][cbox.DisplayMember] == text) {

Serialize/Deserialize object to binary format

2009-07-14T14:15:00.012-05:00

My original goal is to serialize List and List object, but I believe this method can be applied to other type of objects.using System.Runtime.Serialization.Formatters.Binary;public string SerializeObject(object data){ BinaryFormatter formatter = new BinaryFormatter(); using (MemoryStream ms = new MemoryStream()) { //this is the key: serialize formatter.Serialize(ms, data);

Tips: Prevent SSRS report chaching

2009-06-30T09:13:00.006-05:00

There are many ways to turn off the report cache, but many of them need you to have enough privilege to change the settings. There is one approach that everyone can do: from the url.Append this commend to the end of the url:&rc:emissionTime=633819525738564717The number should be random, and you can do like this:"http://.....&rc:emissionTime=" + DateTime.Now.Ticks;The it's the same trick like this

[eBook]Improving .NET Application Performance and Scalability

2009-06-18T13:51:00.001-05:00

A very good book from MS would like to share with everyone: Improving .NET Application Performance and Scalability You can also read it on-line.

Tips: Use String.IsNullOrEmpty() instead of != "" to check empty string

2009-06-17T15:08:00.009-05:00

According to FxCop's recommendation, use String.IsNullOrEmpty() is a good approach to check the String is empty or not.Case 1://No goodstrUsername != ""Case 2://BetterstrUsername.Length != 0Case 3://The Best!String.IsNullOrEmpty(strUsername)Reason: Equals requires more MSIL instructions than the other two. Length will throw an exception is the string is null. IsNullOrEmpty has the same

Download a single file from the remote FTP site (Updated)

2009-06-10T14:06:00.025-05:00

Three approaches to download a file from FTP server: WebRequest, FtpWebRequest, and WebClient. Here are the examples:url = "ftp://xxx.xxx.xxx.xxx/test.txt"WebRequestusing System.Net; //don't forget thispublic string DownloadFile(string url, string username, string pw){ string strResult = ""; try { //According to the rule below, we should pass Uri object instead of string.

ASP.Net: State Management

2009-06-02T11:54:00.003-05:00

I strongly recommend this document (from MS) if you would like to truly understand this topic.

ASP.Net: Browser Capabilities

2009-05-29T08:48:00.012-05:00

I learn from Ramp Up. This is useful if you want to know client support javascript or not.HttpBrowserCapabilities browser = Request.Browser;Label1.Text = "Browser Capabilities\n" + "Type = " + browser.Type + "\n" + "Name = " + browser.Browser + "\n" + "Version = " + browser.Version + "\n" + "Major Version = " + browser.MajorVersion + "\n" + "Minor Version = " + browser.MinorVersion + "\n" +

Javascript: Get client's TimeZone

2009-05-22T11:51:00.009-05:00

How to know client's time and time zone? The simplest way that can do this is using the javascript.