c# - Socket接收数据时设置ReceiveTimeout

Question

我有一个使用 Socket 的客户端，其接收数据的代码如下。

/** Some Code Above **/
private static ManualResetEvent receiveDone = new ManualResetEvent(false);
byte[] receivedBytes = new byte[65535];
String msg = null;

public String ReceiveMessage() {
    csocket.BeginReceive(receivedBytes, 0, receivedBytes.Length, SocketFlags.None, new AsyncCallback(receiveCallback), csocket);
    receiveDone.WaitOne();
    return msg;
}

private void receiveCallback(IAsyncResult ar){
    try{
        Socket socket = (Socket)ar.AsyncState;
        socket.ReceiveTimeout = 10000;  /**** Not  Working ****/
        int received = socket.EndReceive(ar);
        byte[] dataBuf = new byte[received];
        Array.Copy(receivedBytes, dataBuf, received);
        msg = (Encoding.ASCII.GetString(dataBuf)); 
        Console.WriteLine("Message Received: " + msg);
        receiveDone.Set();
    }catch (SocketException e){
        if (e.SocketErrorCode == SocketError.TimedOut){
            Console.WriteLine("SocketExecption => Timeout");
        }else{
            Console.WriteLine("SocketExecption => " + e.ToString());
        }
    }catch (Exception e){
        Console.WriteLine("Execption => " + e.ToString());
    }
}

数据正在接收，但我已将 ReceiveTimeout 设置为 10000，但它不起作用。我是否将 ReceiveTimeout 放在了错误的行中？如果是这样，那么我应该在哪里初始化 ReceiveTimeout？

我发现下面的代码中设置了 ReceiveTimeout 并且可以正常工作，但我更喜欢使用 BeginReceive() 方法。

try{
    byte[] byt = new byte[65535];
    socket.ReceiveTimeout = 10000;
    socket.Receive(byt);
    Console.WriteLine("Message: " + Encoding.UTF8.GetString(byt));
}catch (SocketException e){
    if (e.SocketErrorCode == SocketError.TimedOut)
    {
        Console.WriteLine("TimeOut");
    }else{
        Console.WriteLine("Unknown SocketExecption: " + e.ToString());
    }
}catch (Exception e){
    Console.WriteLine("Unknown Exception:" + e.ToString());
}

这让我在设置 ReceiveTimeout 时感到困惑。

Answer 1

可能重复: How to handle timeout in Async Socket?

ReceiveTimeout 不适用于异步调用。建议的解决方案是使用自己的计时器。

来自 Socket.ReceiveTimeout 的 msdn :

This option applies to synchronous Receive calls only. If the time-out period is exceeded, the Receive method will throw a SocketException.