Question

So I have the following code:

 CGContextDrawImage(context, CGRectMake(100, 0, 220, self.image.size.height), self.image.CGImage);

basically I am asking CG to draw the image 100 px to the right.. now this works fine.. however to the left of the image I see a white background. How do I change this background to some other color? Say I want a black blackground

Answer 1

Before drawing the image, fill the rect with the desired color:

CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
CGContextFillRect(context, CGRectMake(0, 0, self.image.size.width + 100, self.image.size.height)); //I suppose your rect's width is as much as image's width +100
//Then draw your image
CGContextDrawImage(context, CGRectMake(100, 0, 220, self.image.size.height), self.image.CGImage);

Note: Make sure the rect’s you’re drawing into width is at least the image’s width + 100