事件類型不能是Action <>？

Question

這作品

public event Func<int,int> createEvents; 

但爲什麼不呢？

public event Action<int> createEvents; 

Answer 1

public event Action<int> CreateEvents;

完全有效。也許你的事件處理方法與Action<T>委託不匹配。

也許你有這樣的事情：

public event Action<int> CreateEvents; 
    public event Func<int, int> CreateEvents2; 

    public int OnCreateEvents2(int value) 
    { 
     Func<int, int> handler = CreateEvents2; 
     if (handler != null) return handler(value); 

     return 0; 
    } 

    public void OnCreateEvents(int value) 
    { 
     Action<int> handler = CreateEvents; 
     if (handler != null) handler(value); 
    }