drawRect doesn't draw rect - Objective-C

Question

I just want to draw a rect on a view. This is my code in my UIView subclass:

- (void)drawRect:(CGRect)rect
{
context = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(context, 255.0/255.0, 0.0/255.0, 0.0/255.0, 1);
CGContextAddRect(context, (CGRectMake(20, 20, 20, 20)));

}

When I run it no rect is drawn. What's wrong?

Answer 1

CGContextAddRect just adds a rectangular path to the context. You need to stroke or fill the path as well using CGContextFillPath or CGContextStrokePath.

You can also fill a rect directly with UIRectFill or CGContextFillRect.