Click here to Skip to main content
15,891,423 members
Please Sign up or sign in to vote.
0.00/5 (No votes)
See more:
Hi,
I need example of delegate for asp.net(VB) for showing data on my web page.
Thx
Posted
Comments
raju melveetilpurayil 27-Jun-11 4:42am    
do not forget, google is your friend.

Following links will be useful to you to write any kind of delegates.

A Beginner's Guide to Delegates[^]

Delegates And Events - The Uncensored Story - Part 1[^]

Events and Delegates simplified[^]

Hope this will help!
 
Share this answer
 
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Header : System.Web.UI.UserControl
{
public event ColorChangedEventHandler ColorChanged;
public event LinkClickEventHandler Clicked;
string _texts;
string _text;
public void Page_Init(object sender, EventArgs e)
{
//Wire-up the EventHandler
this.colorList.SelectedIndexChanged += new System.EventHandler(Index_Changed);
if (_texts.IndexOf('$') > 0)
{
string[] Texts = _texts.Split('$');
LinkButton lnk;
Label lbl;
for(int cnt = 0; cnt < Texts.Length; cnt++)
{
lnk = new LinkButton();
lnk.Text = Texts[cnt];
lnk.Click += new EventHandler(lnk_Click);
plc.Controls.Add(lnk);
lbl = new Label();
lbl.Text = "";
plc.Controls.Add(lbl);
}
}
}
public string Text
{
set
{
_text = value;
}
get
{
return _text;
}
}
void lnk_Click(object sender, EventArgs e)
{
LinkButton lb = (LinkButton)sender;
_text = lb.Text;
if (Clicked != null)
{
//Call the Delegate and pass the ColorEventArgs
Clicked(this, e);
}
}
//Method called when the DropDownList value changes
public void Index_Changed(object sender, EventArgs e)
{
//Create a new Arguments Object
ColorEventArgs myArgs = new ColorEventArgs();
//Get the color selected
myArgs.Color =colorList.SelectedItem.Text;
colorList.BackColor = System.Drawing.Color.Blue;
//Check if any method has subscribed for notification
//If you don't do this then an exception gets thrown
//When there are no methods subscribing to the Event
if(ColorChanged!=null)
{
//Call the Delegate and pass the ColorEventArgs
ColorChanged(this, myArgs);
}
}
public string Texts
{
get
{
return _texts;
}
set
{
_texts = value;
}
}
}
public delegate void AddClickEventHandler(object sender,EventArgs e);
//Define a Delegate
public delegate void LinkClickEventHandler(object sender,EventArgs e);
//Define a Delegate
public delegate void ColorChangedEventHandler(object sender, ColorEventArgs e);
//Define a Class that Extends the EventArgs
public class ColorEventArgs : System.EventArgs
{
private string color;
//Color Property
public string Color
{
get
{
return this.color;
}
set
{
this.color = value;
}
}
}
———————————————————————————————————————————————————
Using this in another page. Include the header.ascx file
protected void Page_Load(object sender, EventArgs e)
{
//attach functionality to the events in the header
Header1.ColorChanged += new ColorChangedEventHandler(Header1_ColorChanged);
Header1.Clicked += new LinkClickEventHandler(Header1_Clicked);
Database db = DatabaseFactory.CreateDatabase();
DataSet ds = db.ExecuteDataSet(CommandType.StoredProcedure, "usp_Employees");
}
void Header1_Clicked(object sender, EventArgs e)
{
Response.Write(Header1.Text);
}
void Header1_ColorChanged(object sender, ColorEventArgs e)
{
Response.Write("header color changed" + e.Color);
//throw new Exception("The method or operation is not implemented.");
}
 
Share this answer
 

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)



CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900