System.Net.Sockets in WP8

Question

System.Net.Sockets在WP8上有未知的问题。通信建立在下一个模式上--4个第一个字节--用于包长度，接下来4个字节用于包号和数据。所以4{any}是一个TCP包。接下来的步骤是读取输入的数据。1.读取前8个字节。2.从前4个字节中获取包长度，以确定传入数据的大小。3.将缓冲器调整到适当的大小。4.用偏移量为8字节的缓冲区读取传入数据。我给服务器发送了很多包裹。有时，服务器在传入缓冲区中的响应是有效的，可以逐个读取。

但有时，似乎跳过了来自传入数据的前8个字节，使用步骤1-4，我正在从包的数据中读取前8个字节。

无限回路接收

while (_channel.Opened)
{
    Debug.WriteLine("Wait for incoming... ");
    Stream responseStream = await _channel.Receive();
    HandleIncomingData(responseStream);
}

下面是套接字的代码：

    public async Task<Stream> Receive()
    {
        byte[] buff = new byte[8];
        ManualResetEventSlim mre = new ManualResetEventSlim();

        var args = new SocketAsyncEventArgs();

        args.SetBuffer(buff, 0, buff.Length);

        EventHandler<SocketAsyncEventArgs> completed = (sender, eventArgs) => mre.Set();

        EventHandler<SocketAsyncEventArgs> removeSubscription = (sender, eventArgs) => args.Completed -= completed;

        args.Completed += completed;
        args.Completed += removeSubscription;

        _connectionSocket.ReceiveAsync(args);
        mre.Wait();

        args.Completed -= removeSubscription;

        int len = BitConverter.ToInt32(buff, 0);
        int num = BitConverter.ToInt32(buff, 4);

        if (Math.Abs(_packageNumber - num) < 3)
        {
            Array.Resize(ref buff, len);
            args.SetBuffer(buff, 8, buff.Length - 8);

            args.Completed += completed;
            args.Completed += removeSubscription;
            mre.Reset();
            _connectionSocket.ReceiveAsync(args);
            mre.Wait();
        }
        Debug.WriteLine("Recv TCP package: {0}", args.Buffer.ToDebugString());
        if (args.BytesTransferred == 0)
            throw new SocketException();

        byte[] result = new byte[buff.Length - 8];
        Array.ConstrainedCopy(buff, 8, result, 0, result.Length);
        MemoryStream stream = new MemoryStream(result, false);
        return await Task.FromResult(stream);
    }

Answer 1

这是百分之百的问题与交叉线程。在控制台应用程序中也是如此。如果在这里

mre.Reset();
_connectionSocket.ReceiveAsync(args);
mre.Wait();

在mre.Wait()之前放置Thread.Sleep(n)，其中n>1-所有操作都很好。但这是非常粗鲁的解决办法