一、给图片加上阴影 UIImageView*pageContenterImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"onePageApple.png"]];//添加边框
CALayer*layer = [pageContenterImageView layer];layer.borderColor= [[UIColor whiteColor]CGColor];layer.borderWidth=0.0f;//添加四个边阴影
pageContenterImageView.layer.shadowColor= [UIColor blackColor].CGColor;pageContenterImageView.layer.shadowOffset=CGSizeMake(0,0);pageContenterImageView.layer.shadowOpacity=0.5; pageContenterImageView.layer.shadowRadius=5.0;//添加两个边阴影//pageContenterImageView.layer.shadowColor = [UIColor blackColor].CGColor;//    pageContenterImageView.layer.shadowOffset = CGSizeMake(2, 2);//    pageContenterImageView.layer.shadowOpacity = 0.5; //    pageContenterImageView.layer.shadowRadius = 2.0;//-------------
阴影渲染会严重消耗内存 ,导致程序咔叽./*阴影效果*///添加边框
CALayer*layer = [self.pageContenter layer];layer.borderColor= [[UIColorwhiteColor]CGColor];layer.borderWidth=0.0f;//添加四个边阴影
self.pageContenter.layer.shadowColor= [UIColorblackColor].CGColor;//阴影颜色
self.pageContenter.layer.shadowOffset=CGSizeMake(0,0);//阴影偏移
self.pageContenter.layer.shadowOpacity=0.5;//阴影不透明度
self.pageContenter.layer.shadowRadius=5.0;//阴影半径//添加两个边阴影//self.pageContenter.layer.shadowColor = [UIColor blackColor].CGColor;//self.pageContenter.layer.shadowOffset = CGSizeMake(2, 2);//self.pageContenter.layer.shadowOpacity = 0.5; //self.pageContenter.layer.shadowRadius = 2.0; 
二、给视图加上阴影UIView * content=[[UIView alloc] initWithFrame:CGRectMake(100, 250, 503,  500)]; content.backgroundColor=[UIColor orangeColor];//content.layer.shadowOffset=10;
content.layer.shadowOffset = CGSizeMake(5, 3);content.layer.shadowOpacity = 0.6;content.layer.shadowColor = [UIColor blackColor].CGColor;[self.window addSubview:content];