UIImageView 阴影

// Add background tile
UIImage *bgImage = [UIImage imageNamed:@"embedded_bg.png"];
self.view.backgroundColor = [UIColor colorWithPatternImage:bgImage];

// Add the reference view
UIImage *image = [UIImage imageNamed:@"dccp.jpeg"];
UIImageView *imgView = [[UIImageView alloc] initWithImage:image];
[self.view addSubview:imgView];
imgView.center = self.view.center;

imgView.layer.shadowColor = [UIColor blackColor].CGColor;
imgView.layer.shadowOpacity = 0.7f;
imgView.layer.shadowOffset = CGSizeMake(10.0f, 10.0f);
imgView.layer.shadowRadius = 5.0f;
imgView.layer.masksToBounds = NO;

//如果没有这句，渲染会很卡
UIBezierPath *path = [UIBezierPath bezierPathWithRect:imgView.bounds];
imgView.layer.shadowPath = path.CGPath;

[imgView release];