CAShapeLayer面具视图

本文介绍了CAShapeLayer面具视图的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个问题。我在网上寻找答案，我不明白为什么不工作。我必须做一些我无法弄清楚的愚蠢错误。

I have one problem. I look for the answers on the net and I don't understand why is not working. I must do some stupid mistake which I can't figure it out.

如果我做的话：

- (void)viewDidLoad { [super viewDidLoad]; UIView * view = [[UIView alloc]initWithFrame:CGRectMake(10, 10, 300, 400)]; view.backgroundColor = [UIColor blueColor]; [self.view addSubview:view]; }

它在屏幕上创建蓝色视图，但如果我制作

it create blue view on the screen, but if I make

- (void)viewDidLoad { [super viewDidLoad]; UIView * view = [[UIView alloc]initWithFrame:CGRectMake(10, 10, 300, 400)]; view.backgroundColor = [UIColor blueColor]; [self.view addSubview:view]; CAShapeLayer * layer = [[CAShapeLayer alloc]init]; layer.frame = CGRectMake(10, 10, 30, 30); layer.fillColor = [[UIColor blackColor] CGColor]; view.layer.mask = layer; }

它没有显示任何内容。

it don't show anything.

如果我理解正确，它应该掩盖（10,10,30,30）？

If I understand correctly it should mask at (10,10,30,30)?

推荐答案

您需要在CAShapeLayer上设置路径：

You need to set the path on the CAShapeLayer:

- (void)viewDidLoad { [super viewDidLoad]; UIView * view = [[UIView alloc]initWithFrame:CGRectMake(10, 10, 300, 400)]; view.backgroundColor = [UIColor blueColor]; [self.view addSubview:view]; CAShapeLayer * layer = [[CAShapeLayer alloc]init]; layer.frame = view.bounds; layer.fillColor = [[UIColor blackColor] CGColor]; layer.path = CGPathCreateWithRect(CGRectMake(10, 10, 30, 30), NULL); view.layer.mask = layer; }