事件默認初始

Question

我以前可以利用以下：

public event EventHandler OnComplete = delegate { }; 

我不知道，這是怎麼叫，這是一個「事件默認初始值」？

但問題似乎是從EventArgs派生出來的，創建了我自己的EventHandler並決定使用相同的方法。請參閱：

public class MyEventArgs : EventArgs 
{ 
    int result; 
    public int Result 
    { 
     get 
     { 
      if (exceptionObject == null) 
       return result; 
      else 
       throw new InvalidOperationException(); 
     } 
     internal set { result = value; } 
    } 

    Exception exceptionObject; 
    public Exception ExceptionObject 
    { 
     get { return exceptionObject; } 
     internal set { exceptionObject = value; } 
    } 
} 

public delegate EventHandler MyEventHandler(object sender, MyEventArgs e); 

public class MyOperation 
{ 
    public event MyEventHandler OnOperationComplete = delegate { }; 
} 

所以，行

public event MyEventHandler OnOperationComplete = delegate { }; 

導致該問題。

如何爲「我的」事件進行正確的默認初始化？

Answer 1

public event MyEventHandler OnOperationComplete = (sender, args) => { return null; }; 

我也想你的意思是說：

public delegate void MyEventHandler(object sender, MyEventArgs e); 

不

public delegate EventHandler MyEventHandler(object sender, MyEventArgs e);