title: Adjusting size of in app screenshot
body: <p>I am having problem in taking a screenshot with specific area. 
  I have a tabbar at the bottom and a toolbar at the top. I would like to take a screenshot of the screen between those two bars. Below is my code. How can i improve my code to crop out the bars? </p>
  
  <p>Thanks</p>
  
  <pre><code>CGSize imageSize = [[UIScreen mainScreen] bounds].size;
  if (NULL != UIGraphicsBeginImageContextWithOptions)
      UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
  else
      UIGraphicsBeginImageContext(imageSize);
  
  CGContextRef context = UIGraphicsGetCurrentContext();
  
  // Iterate over every window from back to front
  for (UIWindow *window in [[UIApplication sharedApplication] windows]) 
  {
      if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
      {
          // -renderInContext: renders in the coordinate space of the layer,
          // so we must first apply the layer's geometry to the graphics context
          CGContextSaveGState(context);
          // Center the context around the window's anchor point
          CGContextTranslateCTM(context, [window center].x, [window center].y);
          // Apply the window's transform about the anchor point
          CGContextConcatCTM(context, [window transform]);
          // Offset by the portion of the bounds left of and above the anchor point
          CGContextTranslateCTM(context,
                                -[window bounds].size.width * [[window layer] anchorPoint].x,
                                -[window bounds].size.height * [[window layer] anchorPoint].y);
  
          // Render the layer hierarchy to the current context
          [[window layer] renderInContext:context];
  
          // Restore the context
          CGContextRestoreGState(context);
      }
  }
  
  // Retrieve the screenshot image
  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  
  UIGraphicsEndImageContext();
  
  
  
  
  UIImageWriteToSavedPhotosAlbum(image, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), nil);
  </code></pre>