UIView with rounded rectangle and drop shadow: shadow appears above rectangle

Question

I've got a uiview subclass where I'm trying to draw a rounded rectangle with a drop shadow. Though it draws both elements, I can see shadow through the rounded rectangle fill. I'm new to CG so I'm probably missing something simple (though it doesn't seem to be the alpha of the fill which is set to 1). Here's the draw rect code.

- (void)drawRect:(CGRect)rect {
    // get the contect
 CGContextRef context = UIGraphicsGetCurrentContext();

 //for the shadow, save the state then draw the shadow
 CGContextSaveGState(context);
    CGContextSetShadow(context, CGSizeMake(4,-5), 10);



 //now draw the rounded rectangle
 CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
 CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);

 //since I need room in my rect for the shadow, make the rounded rectangle a little smaller than frame
 CGRect rrect = CGRectMake(CGRectGetMinX(rect), CGRectGetMinY(rect), CGRectGetWidth(rect)-30, CGRectGetHeight(rect)-30);
 CGFloat radius = self.cornerRadius;
 // the rest is pretty much copied from Apples example
 CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect);
 CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect);

 // Start at 1
 CGContextMoveToPoint(context, minx, midy);
 // Add an arc through 2 to 3
 CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
 // Add an arc through 4 to 5
 CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
 // Add an arc through 6 to 7
 CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
 // Add an arc through 8 to 9
 CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
 // Close the path
 CGContextClosePath(context);
 // Fill & stroke the path
 CGContextDrawPath(context, kCGPathFillStroke);

 //for the shadow
  CGContextRestoreGState(context);
}

Answer 1

I don't think you can do this in a single pass. Hmm I changed your code as follows, which seems to work.

- (void)drawRect:(CGRect)rect
{
    // get the contect
    CGContextRef context = UIGraphicsGetCurrentContext();

    //now draw the rounded rectangle
    CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
    CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 0.0);

    //since I need room in my rect for the shadow, make the rounded rectangle a little smaller than frame
    CGRect rrect = CGRectMake(CGRectGetMinX(rect), CGRectGetMinY(rect), CGRectGetWidth(rect)-30, CGRectGetHeight(rect)-30);
    CGFloat radius = 45;
    // the rest is pretty much copied from Apples example
    CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect);
    CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect);

    {
        //for the shadow, save the state then draw the shadow
        CGContextSaveGState(context);

        // Start at 1
        CGContextMoveToPoint(context, minx, midy);
        // Add an arc through 2 to 3
        CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
        // Add an arc through 4 to 5
        CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
        // Add an arc through 6 to 7
        CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
        // Add an arc through 8 to 9
        CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
        // Close the path
        CGContextClosePath(context);

        CGContextSetShadow(context, CGSizeMake(4,-5), 10);
        CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);

        // Fill & stroke the path
        CGContextDrawPath(context, kCGPathFillStroke);

        //for the shadow
        CGContextRestoreGState(context);
    }

    {
        // Start at 1
        CGContextMoveToPoint(context, minx, midy);
        // Add an arc through 2 to 3
        CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
        // Add an arc through 4 to 5
        CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
        // Add an arc through 6 to 7
        CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
        // Add an arc through 8 to 9
        CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
        // Close the path
        CGContextClosePath(context);

        CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
        CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);       

        // Fill & stroke the path
        CGContextDrawPath(context, kCGPathFillStroke);
    }
}

Answer 2

How do i implement it to my code? I can't get it to work on my UIView.

Answer 3

Try this after you import QuartzCore/QuartzCore.h

yourView.layer.shadowColor = [[UIColor blackColor] CGColor];

yourView.layer.shadowOffset = CGSizeMake(10.0f, 10.0f);

yourView.layer.shadowOpacity = 1.0f;

yourView.layer.shadowRadius = 10.0f;