How to programmatically create a 24bpp bitmap from color array?

Question

I am trying to programatically create a bitmap from an array that contains color data. With the code below, I get 3 duplicate distorted images side by side when displayed in a picturebox. Can somebody tell me where it's going wrong?

    public Bitmap CreateBM(int[,] imgdat)
    {
        Bitmap bitm = new Bitmap(imgdat.GetUpperBound(1) + 1, imgdat.GetUpperBound(0) + 1, PixelFormat.Format24bppRgb);
        BitmapData bitmapdat = bitm.LockBits(new Rectangle(0, 0, bitm.Width, bitm.Height), ImageLockMode.ReadWrite, bitm.PixelFormat);
        int stride = bitmapdat.Stride;

        byte[] bytes = new byte[stride * bitm.Height];
        for (int r = 0; r < bitm.Height; r++)
        {
            for (int c = 0; c < bitm.Width; c++)
            {
                Color color = Color.FromArgb(imgdat[r, c]);
                bytes[(r * bitm.Width) + c * 3] = color.B;
                bytes[(r * bitm.Width) + c * 3 + 1] = color.G;
                bytes[(r * bitm.Width) + c * 3 + 2] = color.R;
            }
        }


        System.IntPtr scan0 = bitmapdat.Scan0;
        Marshal.Copy(bytes, 0, scan0, stride * bitm.Height);
        bitm.UnlockBits(bitmapdat);

        return bitm;
    }
}

Answer 1

You want to increase the index by stride every row instead of just by bitm.Width.

bytes[(r * stride) + c * 3] = color.B;
bytes[(r * stride) + c * 3 + 1] = color.G;
bytes[(r * stride) + c * 3 + 2] = color.R;