Example of event delegation in C #

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Using System;
Using System. Drawing;
Using System. Windows. Forms;

Namespace winform
{
/// <Summary>
/// Description of delgeate.
/// </Summary>
Public partial class delgeate: Form
{
Public delgeate ()
{
//
// The InitializeComponent () call is required for Windows Forms designer support.
//
InitializeComponent ();

//
// TODO: Add constructor code after the InitializeComponent () call.
//
BtnOne. Click + = new EventHandler (ButtonClick );


}

Public void ButtonClick (object sender, EventArgs e)
{
MessageBox. Show ("btnOne delegate event! ");

}

Void BtnOneClick (object sender, EventArgs e)
{
MessageBox. Show ("btnOne event! ");

}
}
}

First create a Form delgeate Form, put a button control on it, give it a click event btnOne method, and then customize a ButtonClick () method. Define the btnOne delegate event in the form constructor,

BtnOne. Click + = new EventHandler (ButtonClick); after this operation, we can find that it executes its own click event first and then executes the delegate event.