Objective c - Draw image with rounded corners in drawRect

Question

I have a UITableViewCell subclass with a UIImage as property.
I want to draw the image in drawRect, and to be efficient because this is a table view cell.

I know how to draw the image as it is:

-(void)drawRect:(CGRect)aRect 
{
    CGRect rect = self.bounds;

    [self.image drawInRect:rect];
}

But how can I draw the image with rounded corners, and stay efficient?

BTW I don't want to use UIImageView and then set the layer corner radius because it seams to hurt performance.

score 16 · Accepted Answer · answered May 30 '12 at 10:51

16

You need to create a clipping path:

CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSaveGState(ctx);
CGPathRef clippath = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:radius].CGPath;
CGContextAddPath(ctx, clippath);
CGContextClip(ctx);
[self.image drawInRect:rect];
CGContextRestoreGState(ctx);

answered May 30 '12 at 10:51

Svein Halvor Halvorsen

2,474
1
16
14

You can also set the `cornerRadius` property of the underlying core animation layer, but clipping in the `drawRect:` method is more efficient. – Svein Halvor Halvorsen May 30 '12 at 10:55
First: What have you tried? Take a look at `CGContextDrawPath` and `CGContextSetShadowWithColor` and come back if you need more help. – Svein Halvor Halvorsen May 30 '12 at 11:42

Objective c - Draw image with rounded corners in drawRect

1 Answers1