Custom Event Handling in C Sharp .NET with Delegates

This is easy example for Custom Events Handling.

1.Create a form with two label and two text box and two button with the text "Add" and "Clear"

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace CustomEvents2

{

public delegate void MyCustomEvents(string target);

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

public int txt_val1, txt_val2;

public int aval, bval;

TextBox txt1 = new TextBox();

TextBox txt2 = new TextBox();

TextBox txt3 = new TextBox();

Button btn = new Button();

public event MyCustomEvents MyEvents;

private void Form1_Load(object sender, EventArgs e)

{

Label lbl1 = new Label();

lbl1.Text = "Enter A value";

lbl1.Location = new Point(0, 100);

txt1.Location = new Point(100, 100);

txt1.Text = "";

Label lbl2 = new Label();

lbl2.Text = "Enter B value";

lbl2.Location = new Point(0, 150);

txt2.Location = new Point(100, 150);

txt2.Text = "";

Label lbl3 = new Label();

lbl3.Text = "A + B is";

lbl3.Location = new Point(0, 170);

txt3.Location = new Point(100, 175);

btn.Location = new Point(100, 225);

btn.Text = "add";

this.Controls.Add(lbl1);

this.Controls.Add(txt1);

this.Controls.Add(lbl2);

this.Controls.Add(txt2);

this.Controls.Add(lbl3);

this.Controls.Add(txt3);

}

public class MyButttonEvent : Button

{

//constructors

public MyButttonEvent()

{

// this.Click += new MyCustomEvents(this,m1.Addition);

}

}

private void button1_Click(object sender, EventArgs e)

{

aval = Convert.ToInt32(txt1.Text);

bval = Convert.ToInt32(txt2.Text);

this.MyEvents += new MyCustomEvents(Addition);

if (aval != 0 && bval != 0)

if (this.MyEvents != null)

this.MyEvents("add");

}

public void Addition(string t)

{

txt_val1 = Convert.ToInt32(txt1.Text);

txt_val2 = Convert.ToInt32(txt2.Text);

txt3.Text = (txt_val1 + txt_val2).ToString();

}

private void button2_Click(object sender, EventArgs e)

{

txt1.Text = "";

txt2.Text = "";

txt3.Text = "";

}

}

}