預計與IAsyncResult BeginSend

Question

方法嗨我想創建一個TAP包裝。 ConnectTaskAsync很好，但是我在SendTaskAsync方面遇到了一些困難。

public static Task ConnectTaskAsync(this Socket socket, EndPoint endpoint) 
     { 
      return Task.Factory.FromAsync(socket.BeginConnect, socket.EndConnect, endpoint, null); 
     } 

    public static Task<int> SendTaskAsync(this Socket socket, byte[] buffer, int offset, int size, SocketFlags flags) 
    { 
     return Task<int>.Factory.FromAsync(socket.BeginSend, buffer, offset, size, flags, socket.EndSend, null); 
    } 

我得到的錯誤是BeginSend下方的紅色下劃線預計與IAsyncResult的BeginSend的方法

哪兒我去錯了消息？

Answer 1

您的FromAsync定義不正確。不幸的是，沒有一個overload of FromAsync它接受4個單獨的參數（這將需要BeginSend），所以你需要use a different overload：

public static Task<int> SendTaskAsync(this Socket socket, byte[] buffer, int offset, int size, SocketFlags flags) 
{ 
    AsyncCallback nullOp = (i) => {}; 
    IAsyncResult result = socket.BeginSend(buffer, offset, size, flags, nullOp, socket); 
    // Use overload that takes an IAsyncResult directly 
    return Task.Factory.FromAsync(result, socket.EndSend); 
}