C# socket 服务端 异步操作

Question

socket异步C#

Answer 1

我表达错了，我说的死循环是想表达这样一个意思：
就是我BeginReceive读了的数据，第二次读为什么还能把之前的数据都读出来。。我是用Available属性或者EndReceive值来标记应该该读多少数据
客户端用tcpclient的Available都能达到目的

Answer 2

没人舍得看一眼呀，就是想问问为什么这段代码中，已经读取了的数据，之后还能读出来，感觉就是缓存没清空一样或者指针没移动一样
举个列子
客户端发送数据                  服务端接收数据
AAAA                                     AAAA
BBBB                                    AAAABBBB
依次类推
而且，假如客户端只发送一次数据，回调中的Console.WriteLine(str);会无休止执行下去，Available 永远不为0
 private static void ReceiveCallBack(IAsyncResult ar)
        {
            var stateObject = ar.AsyncState as StateObject;
            int readlength = stateObject.CurrentSocket.EndReceive(ar);
            //if (readlength > 0)
            //{
            //    string str = Encoding.GetEncoding("gb2312").GetString(stateObject.buffer, 0, stateObject.CurrentSocket.Available);
            //    Console.WriteLine(str);
            //}
 
            //这里是死循环。。不加这个，连接成功后，客户端只有第一次发送数据能回调，而且readlength还是0，之后客户端再发送数据就不会回调了
            if (stateObject.CurrentSocket.Poll(-1, SelectMode.SelectRead))
            {
                stateObject.CurrentSocket.BeginReceive(stateObject.buffer, 0, stateObject.CurrentSocket.Available, SocketFlags.Peek, new AsyncCallback(ReceiveCallBack), stateObject);
                if (stateObject.CurrentSocket.Available > 0)
                {
                    string str = Encoding.GetEncoding("gb2312").GetString(stateObject.buffer, 0, stateObject.CurrentSocket.Available);
                    Console.WriteLine(str);
                }
            }
        }

Answer 3

娘的，被那博客误导了，下面这个就ok了，持续接后续数据，因为是长连接嘛。
那poll是干啥的安？msdn看了没看懂喃，哪种情景用这玩意儿private static void ReceiveCallBack(IAsyncResult ar)
        {
            var stateObject = ar.AsyncState as StateObject;
            int readlength = stateObject.CurrentSocket.EndReceive(ar);
            if (readlength <= 0)
            {
                stateObject.CurrentSocket.BeginReceive(stateObject.buffer, 0, stateObject.CurrentSocket.Available, SocketFlags.None, new AsyncCallback(ReceiveCallBack), stateObject);
            }
            else
            {
                string str = Encoding.GetEncoding("gb2312").GetString(stateObject.buffer, 0, readlength);
                Console.WriteLine(str);
                stateObject.CurrentSocket.BeginReceive(stateObject.buffer, 0, stateObject.CurrentSocket.Available, SocketFlags.None, new AsyncCallback(ReceiveCallBack), stateObject);
            }
            
            //if (readlength > 0)
            //{
            //    string str = Encoding.GetEncoding("gb2312").GetString(stateObject.buffer, 0, stateObject.CurrentSocket.Available);
            //    Console.WriteLine(str);
            //}            //这里是死循环。。不加这个，连接成功后，客户端只有第一次发送数据能回调，而且readlength还是0，之后客户端再发送数据就不会回调了
            //if (stateObject.CurrentSocket.Poll(-1, SelectMode.SelectRead))
            //{
            //    stateObject.CurrentSocket.BeginReceive(stateObject.buffer, 0, stateObject.CurrentSocket.Available, SocketFlags.Peek, new AsyncCallback(ReceiveCallBack), stateObject);
            //    if (stateObject.CurrentSocket.Available > 0)
            //    {
            //        string str = Encoding.GetEncoding("gb2312").GetString(stateObject.buffer, 0, stateObject.CurrentSocket.Available);
            //        Console.WriteLine(str);
            //    }
            //}
        }

Answer 4

http://blog.csdn.net/jnu_simba/article/details/9042467http://www.2cto.com/net/201310/250365.html

Answer 5

http://wenku.baidu.com/view/694d42360b4c2e3f57276356.html