here is the problem I'm facing: I am making a UIScrollView which will have a pattern image to fill the background. That is to say, I need a background to scroll with the UIScrollView. A good example for this is the Game Center app, on the iPad. The background will scroll smoothly with scrollview.
Currently I have two ways to realize this effect, but neither of them offered good performance. First I tried this
self.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:kRLCastViewBGUnit]];
but unfortunately, the scrolling performance was very bad and occupied too much memory.
Then I tried to use CGContextDrawTiledImage in the drawRect like this:
- (void)drawRect:(CGRect)rect
{
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(currentContext, 0, rect.size.height);
CGContextScaleCTM(currentContext, 1.0, -1.0);
CGContextClipToRect(currentContext, rect);
CGRect centerTileRect = CenterTileRect;
CGContextDrawTiledImage(currentContext, centerTileRect, [ResourceProvider backgroundTileImageRef]);
}
It's still not satisfactory on the new iPad. I must have done something wrong or misused some methods, because the Game Center performs just great when it scrolls. Anyone can offer me a solution to solve the performance issue for the UIScrollView background? Thanks a lot!!