article.aspx.cs

it is the ajax base code use how we use the ajax in th .net

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

using WCPierce.Web;

namespace AJAX
{
  public class Article : System.Web.UI.Page
  {
    protected System.Web.UI.WebControls.TextBox txtUsername;
    protected System.Web.UI.WebControls.Label lblMessage;
    protected System.Web.UI.WebControls.Button btnCheckUsername;
  
    private void Page_Load(object sender, System.EventArgs e) { }

    #region Web Form Designer generated code
    override protected void OnInit(EventArgs e)
    {
      InitializeComponent();
      base.OnInit(e);
    }

    private void InitializeComponent()
    {    
      this.Load += new System.EventHandler(this.Page_Load);

    }
    #endregion

    protected void txtUsername_TextChanged(object sender, System.EventArgs e)
    {
      if( !CallBackHelper.IsCallBack )
        return;

      string uName = txtUsername.Text;

      try
      {
        CallBackHelper.Write( IsUsernameAvailable(uName).ToString() );
      }
      catch( Exception ex )
      {
        CallBackHelper.HandleError( ex );
      }
    }

    protected void btnCheckUsername_Click(object sender, System.EventArgs e)
    {
      string uName = txtUsername.Text;
      if( IsUsernameAvailable( uName ) )
      {
        lblMessage.Text = "PostBack - Username Available!";
        lblMessage.ForeColor = Color.Green;
        lblMessage.Visible = true;
      }
      else
      {
        lblMessage.Text = "PostBack - Username Unavailable!";
        lblMessage.ForeColor = Color.Red;
        lblMessage.Visible = true;
      }

      //Simulate 5 second delay
      System.Threading.Thread.Sleep(5000);
    }

    private bool IsUsernameAvailable( string Username )
    {
      bool isAvailable = true;

      switch( Username.ToLower() )
      {
        case "bill":
        case "william":
        case "christopher":
        case "pierce":
        case "zonebit":
          isAvailable = false;
          break;
      }

      return isAvailable;
    }
  }
}