c#中的事件运用

using System;

namespace Component
{
 /// <summary>
 /// Class1 的摘要说明。
 /// </summary>
 ///
 //声明委托类型
 public delegate void ChangedEventHandler(object sender, EventArgs e);
 
 public class EventString
 {
  private string _name;
  private string _value;

  public string Name
  {
   set{this._name=value;}
   get{return this._name == null?string.Empty:this._name;}
  }
  public string Value
  {
   set
   {
    this._value=value;
    Changed(System.EventArgs.Empty);
   }
   get{return this._value == null?string.Empty:this._value;}
  }
  //声明事件
  public event ChangedEventHandler OnChanged;

  #region
  public EventString(string name)
  {
   this.Name = name;
  }
  #endregion
  // 定义调用事件方法
  #region
  protected virtual void Changed(EventArgs e)
  {
   //调用事件
   if (OnChanged != null)
    OnChanged(this, e);
  }
  #endregion
 }
}



使用:

   EventString  est = new   EventString("demoName");
   //与事件挂钩
   est.OnChanged +=new ChangedEventHandler(est_Changed);
   est.Value="demoValue";