ios - 如何向被屏蔽自定义内容的CALayer添加阴影

Question

我正在尝试向遮罩的UIView(从UIImage)添加阴影，但是我相信因为视图被遮罩到边界，所以masksToBounds = YES不会显示阴影。

如果确实如此，那么我该如何在蒙版图像周围绘制阴影？

-(UIView *)modifyViewWithMask:(UIView *)view
{
    view.alpha = 0.5;
    UIView *blackView = [[UIView alloc] initWithFrame:view.bounds];
    blackView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    blackView.backgroundColor = [UIColor colorWithWhite:0 alpha:0.3];
    [view addSubview:blackView];


    UIImage* bubbleImage = [UIImage imageNamed:@"Bubble"];

    CALayer* mask = [CALayer layer];
    mask.contents = (id)[bubbleImage CGImage];
    mask.frame = CGRectMake(0, 0, view.frame.size.width, view.frame.size.height);
    view.layer.mask = mask;
    view.layer.masksToBounds = YES;


    view.layer.shadowColor = [UIColor blackColor].CGColor;
    view.layer.shadowOffset = CGSizeMake(10, 10);
    view.layer.shadowRadius = 10;
    view.layer.shadowOpacity = 1;


}

Answer 1

像这样尝试设置遮罩的阴影属性而不是view.layer的阴影属性

//mask.shadowColor = [UIColor blackColor].CGColor;
mask.shadowOffset = CGSizeMake(5, 5);
mask.shadowRadius = 2;
mask.shadowOpacity = 1;

请注意，shadowColor属性将被忽略，并且获得与视图相同的颜色。