发送/接收的C#问题字节大小(套接字)

时间:2012-07-31 13:15:03

标签: c# .net sockets

我已经使这些代码发送和接收带有TCP套接字的图像,但接收代码不起作用。

这是发送代码

public void SendImage()
{
    int ScreenWidth = Screen.GetBounds(new Point(0, 0)).Width;
    int ScreenHeight = Screen.GetBounds(new Point(0, 0)).Height;
    Bitmap bmpScreenShot = new Bitmap(ScreenWidth, ScreenHeight);

    Graphics gfx = Graphics.FromImage((Image)bmpScreenShot);
    gfx.CopyFromScreen(0, 0, 0, 0, new Size(ScreenWidth, ScreenHeight));
    bmpScreenShot.Save(Application.StartupPath + "/ScreenShot.jpg", ImageFormat.Jpeg);
    byte[] image = new byte[1];
    bmpScreenShot = ResizeBitmap(bmpScreenShot, 300, 300);

    image = ImageToByte(bmpScreenShot);
    //get the length of image (length of bytes)
    int NumberOfBytes = image.Length;
    //put the size into a byte array
    byte[] numberofbytesArray = BitConverter.GetBytes(NumberOfBytes);

    //send the size to the Client
    int sizesend = sck.Send(numberofbytesArray, 0, numberofbytesArray.Length, 0);
    if (sizesend > 0)
    {
        MessageBox.Show("Size Sent");
    }
    //send the image to the Client
    int imagesend =sck.Send(image, 0, NumberOfBytes, 0);
    if (imagesend > 0)
    {
        MessageBox.Show("Image Sent");
    }
}

这是接收代码

public void ReceiveImage()
{
    if (sck.Connected)
    {
        {
            NetworkStream stream = new NetworkStream(sck);
            byte[] data = new byte[4];

            //Read The Size
            stream.Read(data, 0, data.Length);
            int size = (BitConverter.ToInt32(data,0));
            // prepare buffer
            data = new byte[size];

            //Load Image
            int read = 0;
            while (read != data.Length)
            {
               read += stream.Read(data, read, data.Length - read);
            }
            //stream.Read(data, 0, data.Length);
            //Convert Image Data To Image
            MemoryStream imagestream = new MemoryStream(data);
            Bitmap bmp = new Bitmap(imagestream);
            pictureBox1.Image = bmp;                    
        }
    }
}

问题是当我发送大小时,它发送为5kb但是当我收到它时我发现它是2GB并且出现此错误:

  

无法从传输连接中读取数据。可以执行套接字上的操作,因为系统缺少足够的缓冲区空间或者队列已满。

错误发生在此声明read += stream.Read(data, read, data.Length - read);

1 个答案:

答案 0 :(得分:0)

我会尝试获取更小的数据块。在您的代码中,您开始使用所有数据(在失败的情况下一次2GB。将其降低到更小的数据 - 无论如何数据都以块的形式发送。例如:< / p>

read += stream.Read(buffer, read, 20480);

这将一次读取大约2k,以便不大于缓冲区空间或对队列来说太大。

如果您已经分配了2GB的缓冲区,那么您的应用程序可能只剩下很少的内存。底层框架可能无法为自己分配2GB数据(总共分配4GB)来传输数据。