view边框阴影

//添加边框
CALayer *layer = [someView layer];
layer.borderColor = [[UIColor whiteColor] CGColor];
layer.borderWidth = 5.0f;
//添加四个边阴影
someView.layer.shadowColor = [UIColor blackColor].CGColor;
someView.layer.shadowOffset = CGSizeMake(0, 0);
someView.layer.shadowOpacity = 0.5;
someView.layer.shadowRadius = 10.0;
//添加两个边阴影
someView.layer.shadowColor = [UIColor blackColor].CGColor;
someView.layer.shadowOffset = CGSizeMake(4, 4);
someView.layer.shadowOpacity = 0.5;
someView.layer.shadowRadius = 2.0;