异步套接字缓冲数组的问题

Question

同步套接字接受数据的时候常常是:
byte[] buffer = new byte[64];
string dataReceived = "";
try
{
    while (true)
    {
        int bytesRead = sender.Receive(buffer);
        dataReceived += Encoding.UTF8.GetString(buffer, 0, bytesRead);
        if (dataReceived.IndexOf("\r\n") > -1)
            break;
    }
}
而如果异步套接字这样写,则会报错:
public void ReceiveMsg()
{
    byte[] buffer = new byte[64]; //缓冲字节数组
    serverSocket.BeginReceive(buffer,0,buffer.Length,SocketFlags.None,new AsyncCallback(receiveCallback),buffer);
}
private void receiveCallback(IAsyncResult ar)
{
    try
    {
        byte[] buffer = (byte[])ar.AsyncState; //缓冲字节数组
        StringBuilder sb = new StringBuilder();        while (true)
        {
            int receivedLength = serverSocket.EndReceive(ar);
            sb.Append(Encoding.UTF8.GetString(buffer, 0, receivedLength));
            if (sb.ToString().IndexOf("\r\n") > -1)
                break;
        }
        string msgString = sb.ToString();
        msgString = msgString.Substring(0,msgString.IndexOf("\r\n"));
        Console.WriteLine("收到新消息：{0}",msgString);
    }
    catch (Exception e)
    {
        Console.WriteLine(" 接收数据失败:{0}", e.Message);
    }
    finally
    {
        ReceiveMsg(); //继续监听消息
    }
}报错:只能为每个异步操作调用一次EndReceive。这样的话要接受的信息如果大于64字节就收不了。

Answer 1

public void ReceiveMsg()
        {
            Thread t = new Thread(new ThreadStart(receiveCallback));
            t.Start();
        }
        private void receiveCallback()
        {
byte[] buffer = new byte[64]; 
string dataReceived = ""; 
try 
{ 
    while (true) 
    { 
        int bytesRead = sender.Receive(buffer); 
        dataReceived += Encoding.UTF8.GetString(buffer, 0, bytesRead); 
        if (dataReceived.IndexOf("\r\n")  > -1) 
            break; 
    } 
} 
     }这样行不？

Answer 2

StringBuilder sb = new StringBuilder(); 
byte[] buffer = new byte[64]; //缓冲字节数组 public void ReceiveMsg() 
{ 
    serverSocket.BeginReceive(buffer,0,buffer.Length,SocketFlags.None,new AsyncCallback(receiveCallback),buffer ); 
} private void receiveCallback(IAsyncResult ar) 
{ 
    try 
    { 
        int receivedLength = serverSocket.EndReceive(ar); 
        sb.Append(Encoding.UTF8.GetString(buffer, 0, receivedLength)); 
        if (sb.ToString().IndexOf("\r\n")  > -1) 
        {
            string msgString = sb.ToString(); 
            msgString = msgString.Substring(0,msgString.IndexOf("\r\n")); 
            Console.WriteLine("收到新消息：{0}",msgString); 
        }
    } 
    catch (Exception e) 
    { 
        Console.WriteLine(" 接收数据失败:{0}", e.Message); 
    } 
    finally 
    { 
        ReceiveMsg(); //继续监听消息 
    } 
} 

Answer 3

@jeremyyang824 
谢谢！这样做可以是可以，但有没有更好的办法呢？
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@wzd24 
谢谢！但是如果把循环接受取消掉了，就有违我的最初目的，如果数据超过buffer数组的大小（这里是64）那么消息就会被截断，只返回64字节。因为消息具体大小并不知道，有可能多，有可能少，如果把buffer数组设置的过大，就浪费了资源。