连接到远程主机并使用C#读取数据

Question

我有一台服务器,一旦连接到TCP端口,就会将数据流出.如果你telnet到TCP端口并且数据开始流动,你可以看到这个.

我正在寻找一个示例,让我连接到IP地址和端口,并在应用程序的流中接收数据.

我能找到的所有示例都是客户端 - 服务器模型,客户端发送(这不是我需要的),服务器绑定到自身端口并接收.

我需要这个是异步的,相信这可以做到,但我可以做好腿!

Answer 1

如果您正在使用a TcpClient,GetStream用于获取NetworkStream然后使用流来读取服务器发送的数据.您始终可以使用异步方式使用流BeginRead.

如果您使用的是普通旧设备Socket,则可以BeginReceive在连接后用于异步接收.

无论哪种方式,只要您拥有绑定和连接NetworkStream的Socket对象或对象,服务器或客户端之间就没有区别.您可以使用客户端代码中的读取服务器示例,通常没有(或很少)修改.

举个例子:

byte[] readBuffer = new byte[1000]; 

{
    TcpClient tcpClient = new TcpClient(serverHost, serverPort);
    NetworkStream stream = tcpClient.GetStream();

    stream.BeginRead(readBuffer, 0, 1000, readHandler, tcpClient);
}

...

byte[] tempBuff = new byte[1000];
int tempBuffSize = 0;

// This is a rough example of reading and handling data
// that is delimited by \r\n. This code most probably is
// missing many edge case handling, so use it only as a starting
// point
void readHandler(IAsyncResult result)
{
    TcpClient tcpClient = (TcpClient)result.AsyncState;
    int dataLen = tcpClient.GetStream().EndRead();

    int currStart = 0;
    int currEnd = -1;

    for (int i = 0; i < dataLen; i++)
    {
        if (readBuffer[i] == '\r' && i < (readBuffer.Length - 1) &&
            readBuffer[i + 1] == '\n')
        {
            // Set the end of the data
            currEnd = i - 1;

            // If we have left overs from previous runs:
            if (tempBuffSize != 0)
            {
                // Allocate enough space for the joined buffer
                byte[] joinedData = new byte[tempBuffSize + (currEnd - currStart + 1)];

                // Get the leftover from the previous read
                Array.Copy(tempBuff, 0, joinedData, 0, tempBuffSize);

                // And add the current read as well
                Array.Copy(readBuffer, currStart, joinedData, tempBuffSize, (currEnd - currStart + 1));

                // Now handle it
                HandleData(joinedData, 0, joinedData.Length);

                // Mark that we don't have any leftovers anymore
                tempBuffSize = 0;
            }
            else
            {               
                // Handle the data, from the start to the end, between delimiter
                HandleData(readBuffer, currStart, currEnd);
            }

            // Set the new start - after our delimiter
            currStart = i + 2;
        }
    }

    // See if we still have any leftovers
    if (currStart < dataLen)
    {
        Array.Copy(readBuffer, currStart, tempBuff, 0, dataLen - currStart);
        tempBuffSize = dataLen - currStart;
    }

    // Set the asynchronous read again
    stream.BeginRead(readBuffer, 0, 1000, readHandler, tcpClient);
}