CALayer

http://www.iphone-geek.cn/%E7%BC%96%E7%A8%8B/calayer%E7%AE%80%E5%8D%95%E6%95%99%E7%A8%8B

Java代码 
self.view.layer.backgroundColor = [UIColor orangeColor].CGColor; 
self.view.layer.cornerRadius = 20.0; 
self.view.layer.frame = CGRectInset(self.view.layer.frame, 20, 20); //与4周的距离 
 
用于实现阴影 
CALayer *sublayer = [CALayer layer]; 
sublayer.frame = CGRectMake(30, 30, 128, 192); 
sublayer.borderColor = [UIColor whiteColor].CGColor; 
sublayer.borderWidth = 2.0;     //  边的宽度 
sublayer.cornerRadius = 10.0;   //  圆角半径 
 
sublayer.backgroundColor = [UIColor blueColor].CGColor; 
sublayer.shadowColor     = [UIColor blackColor].CGColor;    //  shadow阴影 
sublayer.shadowOffset = CGSizeMake(20, -10);    //  offset水平、垂直的偏移 
sublayer.shadowRadius = 5.0;    //  半径，影响阴影的点的密集度 
sublayer.shadowOpacity = 0.5;   //  透明度 
[self.view.layer addSublayer:sublayer]; 
 
 
本来这里可以加阴影，但是使用圆角后，会导致阴影失效，故使增加sublayer专门实现阴影 
CALayer *imageLayer = [CALayer layer]; 
imageLayer.frame = sublayer.bounds; 
imageLayer.cornerRadius = 10.0; 
imageLayer.contents = (id) [UIImage imageNamed:@"BattleMapSplashScreen.png"].CGImage; 
imageLayer.masksToBounds = YES; 
[sublayer addSublayer:imageLayer];