字节数组到位图图像

Question

I made this code to receive an image and convert it to bitmap image but it doesn't work.

Here is the code:

public void ReceiveImage()
{
    NetworkStream stream = new NetworkStream(socket);
    byte[] data = new byte[4];
    stream.read(data,0,data.length,0)
    int size = BitConverter.ToInt32(data,0);
    data = new byte[size];
    stream.read(data,0,data.length)
    MemoryStream imagestream = new MemoryStream(data);
    Bitmap bmp = new Bitmap(imagestream);
    picturebox1.Image = bmp;
}

It gets to:

Bitmap bmp = new Bitmap(imagestream);

And gives me this error:

Parameter is not valid

Answer 1

This is an alternative method

int w= 100;
int h = 200;
int ch = 3; //number of channels (ie. assuming 24 bit RGB in this case)

byte[] imageData    = new byte[w*h*ch]; //you image data here
Bitmap bitmap       = new Bitmap(w,h,PixelFormat.Format24bppRgb);
BitmapData bmData   = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
IntPtr pNative      = bmData.Scan0;
Marshal.Copy(imageData,0,pNative,w*h*ch);
bitmap.UnlockBits(bmData);

Answer 2

You are probably not receiving enough bytes in stream.read(data,0,data.length) since Read does not ensure that it will read data.length bytes. you have to check its return value and continue to read till data.Length bytes are read.

See : Stream.Read Method 's return value

int read = 0;
while (read != data.Length)
{
    read += stream.Read(data, read, data.Length - read);
}

PS: I am assuming length s and read s are typos.

Answer 3

I assume you have a table and want to receive the picture from database.

int cout = ds.Tables["TableName"].Rows.Count;
                if (cout > 0)
                {
                    if (ds.Tables["TableName"].Rows[cout - 1]["Image"] != DBNull.Value)
                    {
                        var data = (byte[])(ds.Tables["TableName"].Rows[cout - 1]["Image"]);
                        var stream = new MemoryStream(data);
                        pictureBox1.Image = Image.FromStream(stream);
                    }
                    else
                    {
                        pictureBox1.Image = null;
                    }
                }

Answer 4

尝试这个：

int size = BitConverter.ToInt32(data.Reverse().ToArray(),0);