Objective-C 中的遮罩视图

In 动作脚本3我们可以将蒙版应用到视觉对象，如下所示：

SomeVisualObject.mask = maskShapeObject; 

我怎样才能达到类似的结果Objective-C？假设我有两个UIImageView对象，我想要这样的东西：

imageView1.mask = imageView2;

我怎样才能使用一个UIImageView掩盖或剪辑另一个的形状？

CALayer *maskLayer = [CALayer layer];
 UIImage *maskImage = [UIImage imageNamed:@"maskImage.png"];
maskLayer.contents = (id)maskImage.CGImage;
maskLayer.bounds = (CGRect){CGPointZero, maskImage.size};

UIImageView *imageViewToMask = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
imageViewToMask.image = [UIImage imageNamed:@"image2.png"];
imageViewToMask.layer.mask = maskLayer;