Question

i am new in programming this kind of stuff and a search did not help me out. i found following code on the web and would need to modify it because this is giving me a overflowexception on toint32().

Any help appreciated! thanks

// lock bitmap data
BitmapData  bmData = img.LockBits(
new Rectangle(0, 0, width, height),
ImageLockMode.ReadWrite,
PixelFormat.Format24bppRgb);

// copy image data

int srcStride = bmData.Stride;
int dstStride = bmData.Stride;


      int dst = bmData.Scan0.ToInt32() + dstStride * (height - 1);
      int src = pBuffer.ToInt32();

                for (int y = 0; y < height; y++)
                {
                    Win32.memcpy(dst, src, srcStride);
                    dst -= dstStride;
                    src += srcStride;
                }

// unlock bitmap data
img.UnlockBits(bmData);

Answer 1

Scan0 is a pointer, using ToInt32() will overflow if you run in 64-bit mode. You must use ToInt64() and cast back to IntPtr. Your memcpy() declaration is wrong as well. Some handy declarations:

private static IntPtr AddToPointer(IntPtr ptr, int offset) {
    return new IntPtr(ptr.ToInt64() + offset);
}

[DllImport("msvcrt.dll", CallingConvention = CallingConvention.Cdecl)]
private static extern int memcpy(IntPtr dst, IntPtr src, int bytes);