Visual C#事件與接口程式設計執行個體

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

namespace Events_Interfaces

{

 public delegate void dele();//聲明代表 delegate 關鍵字通知編譯器 dele 是一個委托類型

 public interface IEvents    //定義接口IEvents，包含方法FireEvent事件event1

 {

  event dele event1;

  void FireEvent();

 }

 public class Form1 : System.Windows.Forms.Form

  private System.Windows.Forms.Label label1;

  private System.Windows.Forms.TextBox textBox1;

  private System.Windows.Forms.Label label2;

  private System.Windows.Forms.Button button1;

  private System.Windows.Forms.Label label3;

  private System.ComponentModel.Container components =null;

  public Form1()

  {

   InitializeComponent();

  }

  protected override void Dispose( bool disposing )

   if( disposing )

   {

    if (components != null)

    {

     components.Dispose();

    }

   }

   base.Dispose( disposing );

  #region Windows Form Designer generated code

  private void InitializeComponent()

   this.textBox1 = new System.Windows.Forms.TextBox();

   this.label1 = new System.Windows.Forms.Label();

   this.button1 = new System.Windows.Forms.Button();

   this.label2 = new System.Windows.Forms.Label();

   this.label3 = new System.Windows.Forms.Label();

   this.SuspendLayout();

   this.textBox1.Location = new System.Drawing.Point(8, 80);

   this.textBox1.Name = "textBox1";

   this.textBox1.Size = new System.Drawing.Size(56,23);

   this.textBox1.TabIndex = 1;

   this.textBox1.Text = "";

   this.textBox1.KeyDown += new System.Windows.Forms.KeyEventHandler(this.Key_Press);

   this.label1.Location = new System.Drawing.Point(16, 16);

   this.label1.Name = "label1";

   this.label1.Size = new System.Drawing.Size(256,64);

   this.label1.TabIndex = 0;

   this.label1.Text = "Whenever you use the arrow keys inside the text box, Corresponding events will be" +"fired to display the label appropriately. Have a try!!";

   this.button1.Location = new System.Drawing.Point(240, 112);

   this.button1.Name = "button1";

   this.button1.Size = new System.Drawing.Size(48,23);

   this.button1.TabIndex = 3;

   this.button1.Text = "Exit";

   this.button1.Click += new System.EventHandler(this.button1_Click);

   //

   // label2

   this.label2.Location = new System.Drawing.Point(88, 80);

   this.label2.Name = "label2";

   this.label2.Size = new System.Drawing.Size(184,23);

   this.label2.TabIndex = 2;

   this.label2.TextAlign =System.Drawing.ContentAlignment.MiddleCenter;

   // label3

   this.label3.Location = new System.Drawing.Point(8, 104);

   this.label3.Name = "label3";

   this.label3.Size = new System.Drawing.Size(64,23);

   this.label3.TabIndex = 4;

   this.label3.TextAlign =System.Drawing.ContentAlignment.MiddleCenter;

   // Form1

   this.AutoScaleBaseSize = new System.Drawing.Size(6, 16);

   this.ClientSize = new System.Drawing.Size(292,141);

   this.Controls.AddRange(new System.Windows.Forms.Control[] {this.label3,this.button1,this.label2,this.textBox1,this.label1});

   this.Font= new System.Drawing.Font("Comic SansMS",8.25F,System.Drawing.FontStyle.Regular,

    System.Drawing.GraphicsUnit.Point,((System.Byte)(0)));

   this.Name = "Form1";

   this.Text = "Events";

   this.ResumeLayout(false);

  #endregion

  static void Main()

   Application.Run(new Form1());

  private void Key_Press(object sender,System.Windows.Forms.KeyEventArgs e)

   textBox1.Text = "";

   label2.Text = "";

   string keyId = e.KeyCode.ToString();

   switch (keyId)//判斷是否按下方向鍵

    case "Right":

     label3.Text = "";

     IEvents id1 = new EventClass1();    //執行個體化一個接口

     id1.event1 += new dele(EventFired1);//定義EventClass1中的事件響應方法

     id1.FireEvent();                    //調用EventClass1中的FireEvent方法，觸發event1 事件，事件調用EventFired1方法

     break;

    case "Left":

     IEvents id2 = new EventClass2();

     id2.event1 += new dele(EventFired2);

     id2.FireEvent();

    case "Down":

     IEvents id3 = new EventClass3();

     id3.event1 += new dele(EventFired3);

     id3.FireEvent();

    case "Up":

     IEvents id4 = new EventClass4();

     id4.event1 += new dele(EventFired4);

     id4.FireEvent();

    default:

     label3.Text = keyId;

  //EventFired1方法

  public void EventFired1()

   label2.Text = "You pressed RIGHT arrow key";

  public void EventFired2()

   label2.Text = "You pressed LEFT arrow key";

  public void EventFired3()

   label2.Text = "You pressed DOWN arrow key";

  public void EventFired4()

   label2.Text = "You pressed UP arrow key";

  private void button1_Click(object sender,System.EventArgs e)

   Application.Exit();

 } 

public class EventClass1 : IEvents//EventClass1繼承接口IEvents

  public event dele event1;//定義事件成員event1

  //當事件發生時

  public void FireEvent()

   event1();//調用事件處理

  public class EventClass2 : IEvents

  public event dele event1;

   event1();

 public class EventClass3 : IEvents

public class EventClass4 : IEvents

   event1();