How can I use CGContextDrawTiledImage to tile an image?

Question

I want to be able to an UI object like a UIImageView and tile an image inside of it.

I have been able to use CGContextDrawTiledImage to update the background in the

Answer 1

Rather than trying to modify a UIImageView, consider subclassing UIView instead. UIImageView is specifically designed for one non-tiled image and some of the internals may be messing you up. It's not really intended to be modified in the way you describe.

In a subclass of UIView (UITiledImageView?) you can use the drawRect: method to do what you want. You can even create ivars for the image, its size and tiling properties for greater flexibility and extensibility.

Updated with sample project: http://github.com/kailoa/6tringle-tiledimageview/tree/master

The relevant drawing code:

- (void)drawRect:(CGRect)rect 
{
    if (TiledImage) {

        //Since we are retaining the image, we append with ret_ref.  this reminds us to release at a later date.
        CGImageRef image_to_tile_ret_ref = CGImageRetain(TiledImage.CGImage); 

        CGRect image_rect;
        image_rect.size = TiledImage.size;  //This sets the tile to the native size of the image.  Change this value to adjust the size of an indivitual "tile."

        CGContextRef context = UIGraphicsGetCurrentContext();

        CGContextDrawTiledImage(context, image_rect, image_to_tile_ret_ref);

        CGImageRelease(image_to_tile_ret_ref);
    }
}