由于系统缺乏足够的缓冲空间或队列已满，无法执行套接字上的操作

while循环以非常高的速率调用BeginReceiveFrom()。在操作系统拔掉插头并拒绝分配更多资源之前，应该不会超过几分之一秒。

你必须这样做不同，调用BeginReceiveFrom只在你收到一些东西。在DoReceiveFrom () .

我所做的是使用"StateObject"类，它包含一个"IAsyncResult"对象。这应该用于TCP和UDP。下面是UDP的一个例子。

    // Used for receiver to signal client that data has been received
    // 'readonly' for .Net 4.8
    private readonly ManualResetEvent receiveDone = new ManualResetEvent(false);
    /// <summary>
    /// Supports async receive on UDP socket
    /// </summary>
    private class StateObject
    {
        // Client socket.  
        public UdpClient workSocket = null;
        // Receive buffer.  
        public byte[] buffer;
        // Received data string.  
        public StringBuilder sb = new StringBuilder();
        //public int bytesRead;
        // receiver state
        public IAsyncResult result;
        public delegate void RecvMethod(IAsyncResult result);
        public void BeginReceive(RecvMethod recvMethod, UdpClient udpClient)
        {
            // Set the socket
            workSocket = udpClient;
            // start async receiver
            result = workSocket.BeginReceive(new AsyncCallback(recvMethod), this);
        }
    }

"Receive"方法(由客户端应用程序调用)检查其状态，并且仅在接收器未发出信号(使用receiveDone)和IAsyncResult时触发。完成为false。

这是这里的关键:如果接收器仍然处于活动状态，不要再次启动它，否则您将浪费系统资源。它占用另一个套接字和缓冲区内存空间，这将影响您的应用程序，通常当您试图与脱机设备通信时。

    /// <summary>
    /// Set up async receive handler
    /// </summary>
    /// <returns></returns>
    public void Receive()
    {
        // if receiver running, no packet received - do not restart receiver!
        // did receiver signal done?
        if (receiveDone.WaitOne(0))
        {
            // yes - do not restart receiver!
        }
        // is receiver still running?
        else if (CurrentState.result != null && !CurrentState.result.IsCompleted)
        {
            // yes - do not restart receiver!
        }
        else
        {
            // Begin receiving the data from the remote device.
            CurrentState.BeginReceive(ReceiveCallback, udpClient);
        }
    }

接收回调是这样的:

    /// <summary>
    /// End receive (with blocking) and process received data into buffer
    /// </summary>
    /// <param name="ar">Information about the async operation</param>
    private void ReceiveCallback(IAsyncResult ar)
    {
        // Retrieve the state object and the client socket
        // from the asynchronous state object.
        StateObject st = ar.AsyncState as StateObject;
        UdpClient client = st.workSocket;
        try
        {
            st.buffer = client.EndReceive(ar, ref receivePoint);
            // Read data from the remote device.
            receiveDone.Set();
        }
        // Since this is a callback, catch any error
        // ObjectDisposedException has been seen
        catch (ObjectDisposedException)
        { }
        // "An existing connection was forcibly closed by remote host" has been seen
        // see https://stackoverflow.com/questions/38191968/c-sharp-udp-an-existing-connection-was-forcibly-closed-by-the-remote-host for further information
        catch
        {
        }
    }