public void ReceiveMsg( TcpClient tmpTcpClient )
        {
            try
            {
                if ( tmpTcpClient.Connected )
                {
                    NetworkStream ns = tmpTcpClient.GetStream( );
                    byte[] receiveBytes = new byte[tmpTcpClient.ReceiveBufferSize];
                    FileStream fs = new FileStream( "D:\\aa.png" , FileMode.Create );
                    bool isfirst = true;
                    int i = 0;
                    while ( ns.Read( receiveBytes , 0 , receiveBytes.Length ) > 0 )
                    {

                        if ( isfirst )
                        {
                            fs.Write( receiveBytes , 4 , receiveBytes.Length - 4 );
                            isfirst = false;
                        }
                        else
                        {
                            fs.Write( receiveBytes , 0 , receiveBytes.Length );
                        }
                    }
                    if ( fs != null )
                    {
                        fs.Dispose( );
                    }
                }
            }
            catch ( Exception ex )
            {
                MessageBox.Show( "出问题了" );
            }
        }