One of my projects at Aviary necessitated generating a static UIImage from a UIView. Fortunately, Quartz makes it really simple to do this. Here’s a quick category on UIView showing how it can be done.
To explain: -createImageFromRect: method generates an image by rendering the portion of the view bounded by “frame” in an image context. Note that CALayer’s -renderInContext: method renders the entire layer tree, creating a flat image from the view hierarchy.
/* implementation UIView (UIImageCreation) */
- (UIImage *)createImageFromRect:(CGRect)frame
{
UIGraphicsBeginImageContext(frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGPoint origin = [self bounds].origin;
CGPoint offset = frame.origin;
CGContextTranslateCTM(context, origin.x - offset.x, origin.y - offset.y);
[[self layer] renderInContext:context];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
- (UIImage *)createImage
{
return [self createImageFromRect:[self bounds]];
}
/* end */