CAShapeLayer* shadowLayer = [CAShapeLayerlayer];
[shadowLayersetFrame:_imageView.bounds];
// Standard shadow stuff
[shadowLayersetShadowColor:[[UIColorcolorWithWhite:0alpha:0.8]CGColor]];
[shadowLayersetShadowOffset:CGSizeMake(0.0f,0.0f)];
[shadowLayersetShadowOpacity:1.0f];
// Causes the inner region in this example to NOT be filled.
[shadowLayersetFillRule:kCAFillRuleEvenOdd];
// Create the larger rectangle path.
CGMutablePathRefpath =CGPathCreateMutable();
CGPathAddRect(path,NULL,CGRectInset(_imageView.bounds, -42, -42));
// Add the inner path so it's subtracted from the outer path.
// someInnerPath could be a simple bounds rect, or maybe
// a rounded one for some extra fanciness.
CGPathRefsomeInnerPath = [UIBezierPathbezierPathWithRoundedRect:_imageView.boundscornerRadius:10.0f].CGPath;
CGPathAddPath(path,NULL, someInnerPath);
CGPathCloseSubpath(path);
[shadowLayersetPath:path];
CGPathRelease(path);
[[_imageViewlayer]addSublayer:shadowLayer];
CAShapeLayer* maskLayer = [CAShapeLayerlayer];
[maskLayersetPath:someInnerPath];
[shadowLayersetMask:maskLayer];
