事件委托实例

 一个 算术的事件委托 例子

 

文本框中输入两个数字，按不同的按钮做不同的算法（太差劲的例子，不同的按钮不同的方法就可以了）

 

我们这里用事件委托的思路

 

 

 定义一个 Cmath类

1. 定义一个委托事件　：public delegate void MathHandler(double num1, double num2);
2. 实例化它 : public MathHandler Mathing = null;
3. 最后用一个公共方法调用这个事件
       public void MathRun()
           {
               //引发事件
               Mathing(_num1, _num2);
           }

如下全代码

Cmath.cs

 using System; using System.Collections.Generic; using System.Text; using System.Windows.Forms; namespace DelegateMath { class CMath { private double _num1; private double _num2; //定义一个委托事件 public delegate void MathHandler(double num1, double num2); //实例化这个事件 public MathHandler Mathing = null; /// <summary> /// 构造函数 /// </summary> /// <param name="vNum1"></param> /// <param name="vNum2"></param> public CMath(double vNum1, double vNum2) { _num1 = vNum1; _num2 = vNum2; } /// <summary> /// 公共方法调用委托好的自定义事件 /// </summary> public void MathRun() { //引发事件 Mathing(_num1, _num2); } } }

 

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 DelegateMath { public partial class Form1 : Form { public Form1() { InitializeComponent(); } /// <summary> /// + /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button1_Click(object sender, EventArgs e) { //实例化CMath类 CMath cMath = new CMath(Convert.ToDouble(textBox1.Text.Trim()), Convert.ToDouble(textBox2.Text.Trim())); //加入事件序列 cMath.Mathing += new CMath.MathHandler(MathADD); cMath.MathRun(); } private void MathADD(double num1, double num2) { double num3 = num1 + num2; textBox3.Text = num3.ToString(); } /// <summary> /// - /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button2_Click(object sender, EventArgs e) { //实例化CMath类 CMath cMath = new CMath(Convert.ToDouble(textBox1.Text.Trim()), Convert.ToDouble(textBox2.Text.Trim())); //加入事件序列 cMath.Mathing += new CMath.MathHandler(MathJian); cMath.MathRun(); } private void MathJian(double num1, double num2) { double num3 = num1 - num2; textBox3.Text = num3.ToString(); } /// <summary> /// * /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button3_Click(object sender, EventArgs e) { //实例化CMath类 CMath cMath = new CMath(Convert.ToDouble(textBox1.Text.Trim()), Convert.ToDouble(textBox2.Text.Trim())); //加入事件序列 cMath.Mathing += new CMath.MathHandler(MathChen); cMath.MathRun(); } private void MathChen(double num1, double num2) { double num3 = num1 * num2; textBox3.Text = num3.ToString(); } /// <summary> /// / /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button4_Click(object sender, EventArgs e) { //实例化CMath类 CMath cMath = new CMath(Convert.ToDouble(textBox1.Text.Trim()), Convert.ToDouble(textBox2.Text.Trim())); //加入事件序列 cMath.Mathing += new CMath.MathHandler(MathQu); cMath.MathRun(); } private void MathQu(double num1, double num2) { double num3 = num1 / num2; textBox3.Text = num3.ToString(); } } }