A processing program for custom events

 

For example, this example is written in accordance with "C # practical program design tutorial" (Tang Yao,

Set the Tag attribute of each button to 0, 1, 2, 3, 4,-1.

The Code is as follows.

Create two classes. One is the event class and the other is the Break class.

The Code is as follows:

// Break. cs

Using System;
Using System. Collections. Generic;
Using System. Text;

Namespace WinFormEvent
{

Class Break
{
Public delegate void BreakHandler (object sender, BreakArgs e );
Public event BreakHandler changeBreak;

Public void onChangeBreak (object sender, BreakArgs e)
{
If (changeBreak! = Null)
{
ChangeBreak (sender, e );
}
}

}
}

// BreakArgs. cs

Using System;
Using System. Collections. Generic;
Using System. Text;

Namespace WinFormEvent
{
Class BreakArgs: EventArgs
{
Private int I;

Public int Level
{
Get
{
Return I;
}
Set
{
I = value;
}
}

}
}

// Form1.cs

Using System;
Using System. Collections. Generic;
Using System. ComponentModel;
Using System. Data;
Using System. Drawing;
Using System. Text;
Using System. Windows. Forms;

Namespace WinFormEvent
{
Public partial class Form1: Form
{
Public Form1 ()
{
InitializeComponent ();
Button1. Click + = new System. EventHandler (this. btnStart_Click );
Button2.Click + = new System. EventHandler (this. btnStart_Click );
Button3.Click + = new System. EventHandler (this. btnStart_Click );
Button4.Click + = new System. EventHandler (this. btnStart_Click );
BtnBack. Click + = new System. EventHandler (this. btnStart_Click );
}

Private void btnStart_Click (object sender, EventArgs e)
{
Break B = new Break ();
B. changeBreak + = new WinFormEvent. Break. BreakHandler (B _changeBreak );
BreakArgs ee = new BreakArgs ();
Switch (Convert. ToInt32 (Button) sender). Tag ))
{
Case 0:
Ee. Level = 0;
Break;
Case 1:
Ee. Level = 1;
Break;
Case 2:
Ee. Level = 2;
Break;
Case 3:
Ee. Level = 3;
Break;
Case 4:
Ee. Level = 4;
Break;
Case-1:
Ee. Level =-1;
Break;
}
B. onChangeBreak (sender, ee );
}

Void B _changeBreak (object sender, BreakArgs e)
{
Switch (e. Level)
{
Case 0:
Label1.Text = "start ";
Break;
Case 1:
Label1.Text = "Level 1 ";
Break;
Case 2:
Label1.Text = "Level 2 ";
Break;
Case 3:
Label1.Text = "Level 3 ";
Break;
Case 4:
Label1.Text = "file 4 ";
Break;
Case-1:
Label1.Text = "Inverted ";
Break;
}
// Throw new Exception ("The method or operation is not implemented .");
}

}
}

// Form1.Designer. cs

Namespace WinFormEvent
{
Partial class Form1
{
/// <Summary>
/// Required designer variables.
/// </Summary>
Private System. ComponentModel. IContainer components = null;

/// <Summary>
/// Clear all resources in use.
/// </Summary>
/// <Param name = "disposing"> If the managed resource should be released, the value is true; otherwise, the value is false. </Param>
Protected override void Dispose (bool disposing)
{
If (disposing & (components! = Null ))
{
Components. Dispose ();
}
Base. Dispose (disposing );
}

# Region code generated by Windows Form Designer

/// <Summary>
/// The designer supports the required methods-do not
/// Use the code editor to modify the content of this method.
/// </Summary>
Private void InitializeComponent ()
{
This. label1 = new System. Windows. Forms. Label ();
This. groupBox1 = new System. Windows. Forms. GroupBox ();
This. btnStart = new System. Windows. Forms. Button ();
This. button2 = new System. Windows. Forms. Button ();
This. button3 = new System. Windows. Forms. Button ();
This. button4 = new System. Windows. Forms. Button ();
This. button1 = new System. Windows. Forms. Button ();
This. btnBack = new System. Windows. Forms. Button ();
This. groupBox1.SuspendLayout ();
This. SuspendLayout ();
//
// Label1
//
This. label1.AutoSize = true;
This. label1.Location = new System. Drawing. Point (45, 28 );
This. label1.Name = "label1 ";
This. label1.Size = new System. Drawing. Size (41, 12 );
This. label1.TabIndex = 0;
This. label1.Text = "label1 ";
//
// GroupBox1
//
This. groupBox1.Controls. Add (this. btnBack );
This. groupBox1.Controls. Add (this. button1 );
This. groupBox1.Controls. Add (this. button4 );
This. groupBox1.Controls. Add (this. button3 );
This. groupBox1.Controls. Add (this. button2 );
This. groupBox1.Controls. Add (this. btnStart );
This. groupBox1.Location = new System. Drawing. Point (31, 86 );
This. groupBox1.Name = "groupBox1 ";
This. groupBox1.Size = new System. Drawing. Size (589, 94 );
This. groupBox1.TabIndex = 1;
This. groupBox1.TabStop = false;
This. groupBox1.Text = "downloading ";
//
// BtnStart
//
This. btnStart. Location = new System. Drawing. Point (16, 39 );
This. btnStart. Name = "btnStart ";
This. btnStart. Size = new System. Drawing. Size (75, 23 );
This. btnStart. TabIndex = 0;
This. btnStart. Tag = "0 ";
This. btnStart. Text = "start ";
This. btnStart. UseVisualStyleBackColor = true;
This. btnStart. Click + = new System. EventHandler (this. btnStart_Click );
//
// Button2
//
This. button2.Location = new System. Drawing. Point (203, 38 );
This. button2.Name = "button2 ";
This. button2.Size = new System. Drawing. Size (75, 23 );
This. button2.TabIndex = 1;
This. button2.Tag = "2 ";
This. button2.Text = "2 ";
This. button2.UseVisualStyleBackColor = true;
//
// Button3
//
This. button3.Location = new System. Drawing. Point (294, 38 );
This. button3.Name = "button3 ";
This. button3.Size = new System. Drawing. Size (75, 23 );
This. button3.TabIndex = 2;
This. button3.Tag = "3 ";
This. button3.Text = "3 ";
This. button3.UseVisualStyleBackColor = true;
//
// Button4
//
This. button4.Location = new System. Drawing. Point (386, 38 );
This. button4.Name = "button4 ";
This. button4.Size = new System. Drawing. Size (75, 23 );
This. button4.TabIndex = 3;
This. button4.Tag = "4 ";
This. button4.Text = "4 ";
This. button4.UseVisualStyleBackColor = true;
//
// Button1
//
This. button1.Location = new System. Drawing. Point (111, 38 );
This. button1.Name = "button1 ";
This. button1.Size = new System. Drawing. Size (75, 23 );
This. button1.TabIndex = 4;
This. button1.Tag = "1 ";
This. button1.Text = "1 ";
This. button1.UseVisualStyleBackColor = true;
//
// BtnBack
//
This. btnBack. Location = new System. Drawing. Point (481, 38 );
This. btnBack. Name = "btnBack ";
This. btnBack. Size = new System. Drawing. Size (75, 23 );
This. btnBack. TabIndex = 5;
This. btnBack. Tag = "-1 ";
This. btnBack. Text = "reverse ";
This. btnBack. UseVisualStyleBackColor = true;
//
// Form1
//
This. AutoScaleDimensions = new System. Drawing. SizeF (6F, 12F );
This. AutoScaleMode = System. Windows. Forms. AutoScaleMode. Font;
This. ClientSize = new System. Drawing. Size (651,195 );
This. Controls. Add (this. groupBox1 );
This. Controls. Add (this. label1 );
This. Name = "Form1 ";
This. Text = "Form1 ";
This. groupBox1.ResumeLayout (false );
This. ResumeLayout (false );
This. initialize mlayout ();

}

# Endregion

Private System. Windows. Forms. Label label1;
Private System. Windows. Forms. GroupBox groupBox1;
Private System. Windows. Forms. Button btnBack;
Private System. Windows. Forms. Button button1;
Private System. Windows. Forms. Button button4;
Private System. Windows. Forms. Button button3;
Private System. Windows. Forms. Button button2;
Private System. Windows. Forms. Button btnStart;
}
}

The implementation result is as follows:

When you press any button, an event is generated, notifying the Label to display the corresponding information.