Question

我正在开发一个appserver。我想使用AcceptAsync方法。我收到错误“对象引用没有设置为对象的实例。”调用ReceiveAsync方法时。如果有任何问题并得到解决方案吗？

public class AppServer
{
    public void Start()
    {
        Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 12345));
        serverSocket.Listen(100);

        SocketAsyncEventArgs e = new SocketAsyncEventArgs();
        e.Completed += new EventHandler<SocketAsyncEventArgs>(e_Completed);

        bool raiseEvent = serverSocket.AcceptAsync(e);
        if (!raiseEvent)
            AcceptCallback(e);
    }

    void e_Completed(object sender, SocketAsyncEventArgs e)
    {
        AcceptCallback(e);
    }

    private void AcceptCallback(SocketAsyncEventArgs e)
    {
        SocketAsyncEventArgs readEventArgs = new SocketAsyncEventArgs();
        readEventArgs.Completed += new EventHandler<SocketAsyncEventArgs>(readEventArgs_Completed);

        Socket clientSocket = e.AcceptSocket;
        bool raiseEvent = clientSocket.ReceiveAsync(readEventArgs); // <-- Error goes here
        if (!raiseEvent)
            ReceiveCallback(readEventArgs);
    }

    void readEventArgs_Completed(object sender, SocketAsyncEventArgs e)
    {
        ReceiveCallback(e);
    }

    private void ReceiveCallback(SocketAsyncEventArgs e)
    {

    }
}

Answer 1

我有同样的问题，我设法解决了。您需要向SocketAsyncEventArgs对象提供一个数据缓冲区（字节数组），用于存储在调用ReceiveAsync（e）之前接收的数据。

void e_Completed(object sender, SocketAsyncEventArgs e)
{
    byte[] buffer = new byte[1024];
    e.SetBuffer(buffer, 0, buffer.Length);
    AcceptCallback(e);
}

Answer 2

我不确定你为什么在两个地方接受套接字。如果删除

 AcceptCallback(e);

来自e_Completed的

一切正常。

它是示例异步服务器的链接：

a link

C＃ReceiveAsync错误

2 个答案: