UIView 子类中的 CAShapeLayer

Question

我想用掩码创建UIView 的子类。我尝试使用drawRect 和layoutSubviews 但没有成功，在这些尝试中没有出现视图。

- (void)layoutSubviews {
    [super layoutSubviews];

    UIBezierPath *path = [UIBezierPath new];
    [path moveToPoint:(CGPoint){self.frame.origin.x + 10, self.frame.origin.y}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x + self.frame.size.width, self.frame.origin.y}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x + self.frame.size.width, self.frame.origin.y + self.frame.size.height}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x +10, self.frame.origin.y + self.frame.size.height}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x +10, self.frame.origin.y + (self.frame.size.height/2) + 5}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x , self.frame.origin.y + (self.frame.size.height/2)}];
    [path addLineToPoint:(CGPoint){self.frame.origin.x +10, self.frame.origin.y + (self.frame.size.height/2) - 5}];
    [path closePath];
    CAShapeLayer *mask = [CAShapeLayer new];
    mask.frame = self.bounds;
    mask.path = path.CGPath;
    self.layer.mask = mask;
}

我为此覆盖的方法是什么？我看到了很多类似问题的答案，但对我不起作用。

Answer 1

我为此找到了解决方案。我在我的视图中创建另一个视图并在她身上应用蒙版。

代码：

@interface BubbleView()

@property (nonatomic, strong) UIView *maskView;

@end
@implementation BubbleView


-(id) initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];

    self.maskView = [[UIView alloc] init];
    [self addSubview:self.maskView];
    self.backgroundColor = [UIColor colorWithWhite:1.0 alpha:0.0];
    return self;
}

- (void)drawRect:(CGRect)rect {

    self.maskView.frame = self.bounds;
    self.maskView.backgroundColor = [UIColor whiteColor];

   [super drawRect:rect];
}

- (void)layoutSubviews {
    [super layoutSubviews];

    UIBezierPath *path = [UIBezierPath new];
    [path moveToPoint:(CGPoint){self.maskView.frame.origin.x + 10, self.maskView.frame.origin.y}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x + self.maskView.frame.size.width, self.maskView.frame.origin.y}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x + self.maskView.frame.size.width, self.maskView.frame.origin.y + self.maskView.frame.size.height}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x +10, self.maskView.frame.origin.y + self.maskView.frame.size.height}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x +10, self.maskView.frame.origin.y + (self.maskView.frame.size.height/2) + 5}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x , self.maskView.frame.origin.y + (self.maskView.frame.size.height/2)}];
    [path addLineToPoint:(CGPoint){self.maskView.frame.origin.x +10, self.maskView.frame.origin.y + (self.maskView.frame.size.height/2) - 5}];
    [path closePath];

    CAShapeLayer *mask = [CAShapeLayer new];
    mask.frame = self.maskView.bounds;
    mask.path = path.CGPath;
    self.maskView.layer.mask = mask;

    [self layoutIfNeeded];

}