Question

怎么添加自定义事件 ？C#

就是用委托来添加自定义事件的，
给个最简单的示例代码就行！

谢谢大家

Answer 1

delegate viod CharEventHandler(object sender, CharEventArgs e);

//自定义了一个触发事件的参数

public class CharEventArgs : EventArgs

{

public char CurrChar;

public CharEventArgs(char CurrChar)

{

this.CurrChar = CurrChar;

}

}

class CharChecker

{

char curr_char;

public event CharEventHandler CharTest;

public char Curr_Char

{

get{return curr_char;}

set

{

if(CharTest!=null)

{

CharEventArgs myeven=new CharEventArgs(value);

CharTest(this,myeven);// 在这里触发事件

curr_char=myeven.CurrChar

}

}

}

}

class AppEvent

{

static void Main()

{

CharChecker chartester=new CharChecker();

chartester.CharTest+=new CharEventHandler(Change_X);//触发事件Chartest时, 绑定到Change_X函数上

chartester.Curr_Char='a'; //运行Curr_Char的Set方法, 触发事件

Console.WriteLine("事件处理结果：{0}",chartester.Curr_Char);

chartester.Curr_Char='b';

Console.WriteLine("事件处理结果：{0}",chartester.Curr_Char);

chartester.Curr_Char='x';

Console.WriteLine("{0}",chartester.Curr_Char);

Console.WriteLine();

}

static void Change_X(Object source, CharEventArgs e)

{

if(e.CurrChar=='x' || e.CurrChar='X')

{

Console.Write("触发的字符是x,");

Console.Write("把x替为：");

e.CurrChar='?';

}

else

Console.Write("触发的字符不是x,");

}

}

运行结果：

触发的字符不是x,事件处理的结果:a

触发的字符不是x,事件处理的结果:b

触发的字符是x,把x替为：？

Answer 2

static void Main(string[] args)
{
PrintWordsDel mDel;
mDel = PrintWords;
mDel("你好！");

Console.ReadKey();
}
public delegate void PrintWordsDel(string words);
static void PrintWords(string words)
{
Console.WriteLine(words);
}

以上是直接使用委托，下面用委托加事件触发：

class Program
{
static void Main(string[] args)
{

CEventDel mEventDel = new CEventDel();
mEventDel.mDel += new PrintWordsDel(mEventDel.PrintWordsHandler);
mEventDel.PrintWords("你好！");

Console.ReadKey();
}

}
public delegate void PrintWordsDel(string words); //定义委托事件
public class CEventDel
{
public event PrintWordsDel mDel; //委托变量

public void PrintWords(string words) //调用该事件将触发PrintWordsHandler
{
if (mDel != null)
{
mDel(words);
}
}

public void PrintWordsHandler(string words)
{
Console.WriteLine(words);
}
}

Answer 3

public delegate void WebUserControlButtonClickHandler(object sender, EventArgs e);
public event WebUserControlButtonClickHandler ClickHandler;

然后再需要的时候检查事件委托是否不为空并引发，比如按下按钮时
protected void Button1_Click(object sender, EventArgs e)
{
if (ClickHandler != null)
{
ClickHandler(sender, e);
}
}