河南省德威鋼結(jié)構(gòu)工程有限

    代碼，內(nèi)含說明（界面是兩個(gè)文本框textbox1，textbox2，和一個(gè)button1，界面的Load事件，button的click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 Test
    {
    public partial class Form1 : Form
    {
    public Form1()
    {
    InitializeComponent();
    }
    //CustomClass cc = new CustomClass(1, "Lee");//測試屬性值不變化的情況
    CustomClass cc = new CustomClass();//空構(gòu)造函數(shù)，一邊測試屬性值改變
    private void Form1_Load(object sender, EventArgs e)
    {
    cc.Changed += new CustomClass.ChangedEventHandler(cc_Changed);//加載事件
    }
    private void button1_Click(object sender, EventArgs e)
    {
    cc.Cid = 1;
    cc.Cname = "Lee";//給CustomClass的屬性賦值，賦值是引發(fā)事件
    string str = cc.Cid.ToString() + cc.Cname;
    MessageBox.Show(str);
    }
    private void cc_Changed()//事件
    {
    textBox1.Text = cc.Cid.ToString();
    textBox2.Text = cc.Cname;
    }
    }
    public class CustomClass
    {
    public delegate void ChangedEventHandler();//定義委托
    public event ChangedEventHandler Changed;//定義事件
    private int _Cid;
    private string _Cname;
    public CustomClass()
    {
    }
    public CustomClass(int cCid, string cCname)
    {
    this._Cid = cCid;
    this._Cname = cCname;
    }
    protected virtual void OnChanged()
    {
    if (Changed!=null)
    {
    Changed();
    }
    }
    public int Cid
    {
    get
    {
    return _Cid;
    }
    set
    {
    if (_Cid!=value)//這里是文本改變時(shí)的處理
    {
    _Cid = value;
    OnChanged();//啟動事件
    }
    }
    }
    public string Cname
    {
    get
    {
    return _Cname;
    }
    set
    {
    if (_Cname != value)
    {
    _Cname = value;
    OnChanged();
    }
    }
    }
    }
    }
    以下是網(wǎng)上的一段非常經(jīng)典的屬性值改變引發(fā)自定義事件的例子，如下;
    public class MyClass
    {
    public event EventHandler<PropertyChagedEventArgs> MyPropertyChanging;
    public event EventHandler<PropertyChagedEventArgs> MyPropertyChanged;
    private int _myProperty;
    public int MyProperty
    {
    get { return _myProperty; }
    set
    {
    if (value != _myProperty)
    {
    PropertyChagedEventArgs e = new PropertyChagedEventArgs("MyProperty", _myProperty, value);//初始化
    if (this.MyPropertyChanging != null)
    {
    this.MyPropertyChanging(this, e);
    if (e.Cancel) return;
    }
    _myProperty = (int)e.NewValue;
    if (this.MyPropertyChanged != null)
    {
    this.MyPropertyChanged(this, e);
    }
    }
    }
    }
    }
    /// <summary>
    /// 通用的類
    /// </summary>
    public class PropertyChagedEventArgs : EventArgs
    {
    public PropertyChagedEventArgs(string propertyName,object oldValue,object newValue)
    {
    PropertyName = propertyName;
    OldValue = oldValue;
    NewValue = newValue;
    }
    public bool Cancel { get; set; }
    public string PropertyName { get; private set; }
    public object OldValue { get; private set; }
    public object NewValue { get; set; }
    }