I'm trying to use this code to draw a Bitmap directly onto a PictureBox:

Bitmap bmp = (Bitmap)Bitmap.FromFile(@"C:\Users\Ken\Desktop\Load2.bmp");
Graphics grDest = Graphics.FromHwnd(pictureBox1.Handle);
Graphics grSrc = Graphics.FromImage(bmp);
IntPtr hdcDest = grDest.GetHdc();
IntPtr hdcSrc = grSrc.GetHdc();
BitBlt(hdcDest, 0, 0, pictureBox1.Width, pictureBox1.Height,
    hdcSrc, 0, 0, (uint)TernaryRasterOperations.SRCCOPY); // 0x00CC0020
grDest.ReleaseHdc(hdcDest);
grSrc.ReleaseHdc(hdcSrc);

but instead of rendering the Bitmap's contents it just draws a solid block of nearly-black. I'm pretty sure the problem is with the source hDC, because if I change SRCCOPY to WHITENESS in the above code, it draws a solid white block, as expected.

Note: this next snippet works fine, so there's nothing wrong with the bitmap itself:

Bitmap bmp = (Bitmap)Bitmap.FromFile(@"C:\Users\Ken\Desktop\Load2.bmp");
pictureBox1.Image = bmp;