学步园

设计一个可统计单击次数的按钮,它提供一个自定义的MyClick事件

一、使用自定义事件的委托

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace 事件练习
{
    /// <summary>
    /// 自定义按钮可以实现记录点击的次数
    /// </summary>
    public  class MyCustomButton:Button
    {
        /// <summary>
        /// 自定义事件的委托
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public delegate void MyClickDelegate(object sender, MyClickEventArgs e);
        /// <summary>
        /// 自定义事件
        /// </summary>
        public event MyClickDelegate MyClick;
        int clickCount = 0;
        protected   override void OnClick(EventArgs e)
        {
            clickCount++;
            if (MyClick != null)
            {
                //激发MyClick事件
                MyClick(this, new MyClickEventArgs(clickCount));
            }
        }
    }


    /// <summary>
    /// 定义MyClick事件参数
    /// </summary>
    public class MyClickEventArgs : EventArgs
    {
        /// <summary>
        /// 点击次数
        /// </summary>
        public int clickCount = 0;
        public MyClickEventArgs(int clickCountValue)
        {
            this.clickCount = clickCountValue;
        }
    }
}

二、使用泛型事件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace 事件练习
{
    /* 一、泛型委托的定义如下：
    [SerializableAttribute]
    public delegate void EventHandler<TEventArgs>(
    Object sender,
    TEventArgse
    ) where TEventArgs: EventArgs
    */
    /*二、使用EventHandler<>的好处是：
    1.只需定义好事件参数类(从EventArgs类派生)
    2.不再需要定义独立的事件委托.
    */
    /// <summary>
    /// 自定义按钮可以记录点击次数(使用了泛型委托)
    /// </summary>
    public class MyCustomButtonUseGenericscDelegate:Button
    {
        /// <summary>
        /// 使用泛型事件可以简化自定义事件
        /// </summary>
        public event EventHandler<MyClickEventArgs> MyClick;
        int clickCount = 0;
        protected override void OnClick(EventArgs  e)
        {
            clickCount++;
            if (MyClick != null)
            {
                MyClick(this, new MyClickEventArgs(clickCount));
            }
        }
    }
}

三、前台注册事件

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 事件练习
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            //挂载事件
            myCustomButton1.MyClick += new MyCustomButton.MyClickDelegate(myCustomButton1_MyClick);
            myCustomButtonUseGenericscDelegate1.MyClick += new EventHandler<MyClickEventArgs>(myCustomButtonUseGenericscDelegate1_MyClick);
        }

        void myCustomButtonUseGenericscDelegate1_MyClick(object sender, MyClickEventArgs e)
        {
            MessageBox.Show(string.Format("点击了{0}次按钮.", e.clickCount));
        }

        void myCustomButton1_MyClick(object sender, MyClickEventArgs e)
        {
            MessageBox.Show(string.Format("点击了{0}次按钮.", e.clickCount));
        }
    }
}

源代码下载:点击打开链接