Problem with Bitmaps and Graphics

[Dataflashsabot]

I'm new to C#, so please forgive the ~407,000 coding sins I'm probably making.
The purpose of this function is to take a bitmap and return a bitmap of double the height, with two of the images stacked on top of each other.

private Bitmap ProcessBitmap(Bitmap sourceBitmap)
        {
 
 
            int w = sourceBitmap.Width;
            int h = sourceBitmap.Height;
            int targetHeight = (h*2);
 
 
 
            Bitmap targetBitmap = new Bitmap(w, targetHeight);
 
            Rectangle sourceRect = new Rectangle(0, 0, w, h);
 
            Graphics sourceGraphics; 
            sourceGraphics = Graphics.FromImage(sourceBitmap);
            Graphics targetGraphics;
            targetGraphics = Graphics.FromImage(targetBitmap);
 
            // Begin implementation code
 
            targetGraphics.DrawImage(sourceBitmap, 0, 0);
            targetGraphics.DrawImage(sourceBitmap, 0, h);
 
            Bitmap returnBitmap = new Bitmap(w, targetHeight, targetGraphics);
            targetGraphics.Dispose();
 
 
 
            return returnBitmap;
        }

But it seems to return an empty bitmap. Please help, I am at my wit's end. :-)

[Dataflashsabot]

Nevermind, I'm an idiot. The problem was in the code that was taking the return value. On the plus side, I rewrote the whole function trying to solve this, and it's now much neater and cleaner.

[Plater]

Maybe like this:

private Bitmap ProcessBitmap(Bitmap sourceBitmap) 
{ 
   int h = sourceBitmap.Height;
   Bitmap returnBitmap = new Bitmap(sourceBitmap.Width, h*2); 
 
   Graphics targetGraphics = Graphics.FromImage(targetBitmap);
 
   targetGraphics.DrawImageUnscaled(sourceBitmap, 0, 0);
   targetGraphics.DrawImageUnscaled(sourceBitmap, 0, h);
 
   return returnBitmap; 
} 
 

[akshaymahajan]

Please forgive me if I sound rude ... but u don't need int h in your code. Just replace h by sourceBitmap.Height ... Just trying to save some memory space for the application :) .. Hope u don't mind.

[Plater]

You could collapse the code a lot more then just getting rid of the h. Its just there so you can follow along