Question

我曾经使用过以下内容：

public event EventHandler OnComplete = delegate { };

我不确定，这是怎么调用的，这是一个“事件默认初始化器”??

但问题似乎是当我从EventArgs派生时，创建了我自己的EventHandler并决定使用相同的方法。请看：

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 { };

导致问题。

如何为“我的”事件进行正确的默认初始化？

Answer 1

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

我也认为你的意思是：

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

不是

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

事件默认初始化程序

1 个答案: