C#接口编程实例向你讲述了事件与接口的联合应用很多初学C#的朋友对于事件与接口感到迷惑不解,不明白它们之间的关系,下面我就用实例来简单的分析讲解一下。
 
C#接口编程实例问题的解决之前我们来看看事件的创建过程,用event修饰符来代表一个事件,我们要创建一个C#事件必须按以下顺序来扫行:

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C#接口编程实例1,创建或标识一个代表。
比如下例中的
- public delegate void dele();
 - //声明代表,delegate 关键字通知编译器dele是一个委托类型
 
C#接口编程实例2,创建一个包含事件处理代表,调用事件处理代表的方法的类
- public class EventClass1 : IEvents
 - //IEvents,是下面我们要讲一接口
 - {
 - public event dele event1;//定义事件成员event1
 - public void FireEvent() //当事件发生时
 - {
 - event1(); //调用事件处理
 - }
 - }
 
EventClass1继承接口IEvents,以下后面的EventClass2~4,都是一样。
C#接口编程实例3,定义一个或多个把方法连接到事件的类
C#接口编程实例4,使用事件
4.1 定义事件响应方法,如下例中的
IEvents id1 = new EventClass1();
4.2 使用所定义的构造函数创建一个包含事件的对象,如下例中的
id1.event1 += new dele(EventFired1);
4.3 触发事件,如下例中的
id1.FireEvent();
下面我们来看看接口,我们必须用interface来声明一个接口。接口声明可以声明零个或多个成员。接口的成员必须是方法、属性、事件或索引器。接口不能包含常数、字段、运算符、实例构造函数、析构函数或类型,也不能包含任何种类的静态成员。
所有接口成员都隐式地具有 public 访问权限。接口成员声明包含任何修饰符属于编译时错误。具体地说,接口成员包含下列任何修饰符属于编译时错误:abstract、public、protected、internal、private、virtual、override 或 static。更多的信息请看msdn help://MS.VSCC/MS.MSDNVS.2052/csspec/html/vclrfcsharpspec_13_1.htm
在下面的例子中,我们声明IEvents接口,一个方法FireEvent和一个事件event1
- public interface IEvents
 - {
 - event dele event1; //定义事件
 - void FireEvent();//定义接口
 - }
 
在后面的EventClass1~4类是继承了接口IEvent,因此在这几个类中必须实现上述一个方法和一个事件。下面的实例可以帮助大家更好的理解。
这是一个简单的windows Forms,包含一个textbox,几个labels和一个button,在程序启动时焦点在textbox,捕捉键盘按下事件,除方向键外,我能过接口来触事方向键按下事件。#p#
下面的代码是一个网上常见的C#接口编程实例,大家可以拷贝下来,保存为.cs文件,用CSC编译就行
C#接口编程实例代码如下:
- 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();
 - //声明代表 delegate 关键字通知编译器 dele 是一个委托类型
 - public interface IEvents
 - //定义接口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
 - //C#接口编程实例
 - 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
 - //C#接口编程实例
 - 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)//判断是否按下方向键
 - {
 - case "Right":
 - label3.Text = "";
 - IEvents id1 = new EventClass1(); //实例化一个接口
 - id1.event1 += new dele(EventFired1);
 - //定义EventClass1中的事件响应方法
 - id1.FireEvent();
 - //调用EventClass1中的FireEvent方法,
 - //触发event1 事件,事件调用EventFired1方法
 - break;
 - case "Left":
 - label3.Text = "";
 - IEvents id2 = new EventClass2();
 - id2.event1 += new
 - dele(EventFired2);
 - id2.FireEvent();
 - break;
 - case "Down":
 - label3.Text = "";
 - IEvents id3 = new EventClass3();
 - id3.event1 += new
 - dele(EventFired3);
 - id3.FireEvent();
 - break;
 - case "Up":
 - label3.Text = "";
 - IEvents id4 = new EventClass4();
 - id4.event1 += new
 - dele(EventFired4);
 - id4.FireEvent();
 - break;
 - default:
 - label3.Text = keyId;
 - break;
 - }
 - }
 - //EventFired1方法
 - public void EventFired1()
 - {
 - label2.Text = "";
 - label2.Text = "You pressed RIGHT arrow key";
 - }
 - public void EventFired2()
 - {
 - label2.Text = "";
 - label2.Text = "You pressed LEFT arrow key";
 - }
 - public void EventFired3()
 - {
 - label2.Text = "";
 - label2.Text = "You pressed DOWN arrow key";
 - }
 - public void EventFired4()
 - {
 - label2.Text = "";
 - label2.Text = "You pressed UP arrow key";
 - }
 - //C#接口编程实例
 - private void button1_Click(object sender,
 - System.EventArgs e)
 - {
 - Application.Exit();
 - }
 - }
 - public class EventClass1 : IEvents
 - {
 - public event dele event1;
 - public void FireEvent()
 - {
 - event1();
 - }
 - }
 - public class EventClass2 : IEvents
 - {
 - public event dele event1;
 - public void FireEvent()
 - {
 - event1();
 - }
 - }
 - public class EventClass3 : IEvents
 - {
 - public event dele event1;
 - public void FireEvent()
 - {
 - event1();
 - }
 - }
 - public class EventClass4 :
 - IEvents//EventClass1继承接口IEvents
 - {
 - public event dele event1;//定义事件成员event1
 - //当事件发生时
 - public void FireEvent()
 - {
 - event1();//C#接口编程实例之调用事件处理
 - }
 - }
 - }
 
C#接口编程实例的基本内容就向你介绍到这里,希望对你了解和学习C#接口编程有所帮助。