untitled

//镂空效果
- (void)photoFadeout
{
    
    UIView *backgroundView = [[UIView alloc] init];
    backgroundView.frame = self.view.bounds;
    backgroundView.backgroundColor = [UIColor colorWithWhite:0 alpha:0.7];
    [self.view addSubview:backgroundView];
    
    // 创卷一个全屏大Path
    UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.view.bounds];
    
    // 创建一个圆形的Path
    UIBezierPath *circlePath = [UIBezierPath bezierPathWithArcCenter:CGPointMake(self.view.center.x, self.view.center.y - 25)
                                                              radius:50
                                                          startAngle:0
                                                            endAngle:2 *M_PI
                                                           clockwise:NO];
    [path appendPath:circlePath];
    
    
    CAShapeLayer *sharpLayer = [CAShapeLayer layer];
    sharpLayer.path = path.CGPath;
    
    /*
     　　这个方法实现原理应该是path的FillRule 默认是FillRuleEvenOdd(CALayer 有一个fillRule属性的规则就有kCAFillRuleEvenOdd),
        而EvenOdd 是一个奇偶规则,奇数则显示,偶数则不显示.叠加则是偶数故不显示.
     */
    sharpLayer.fillRule = kCAFillRuleEvenOdd;
    backgroundView.layer.mask = sharpLayer;
    
}
- (void)photoFadeout
{
    
    UIView *backgroundView = [[UIView alloc] init];
    backgroundView.frame = self.view.bounds;
    backgroundView.backgroundColor = [UIColor colorWithWhite:0 alpha:0.7];
    [self.view addSubview:backgroundView];
    
    // 创卷一个全屏大Path
    UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.view.bounds];
    
    // 创建一个圆形的Path
    UIBezierPath *circlePath = [UIBezierPath bezierPathWithArcCenter:CGPointMake(self.view.center.x, self.view.center.y - 25)
                                                              radius:50
                                                          startAngle:0
                                                            endAngle:2 *M_PI
                                                           clockwise:NO];
    [path appendPath:circlePath];
    
    
    CAShapeLayer *sharpLayer = [CAShapeLayer layer];
    sharpLayer.path = path.CGPath;
    
    /*
     　　这个方法实现原理应该是path的FillRule 默认是FillRuleEvenOdd(CALayer 有一个fillRule属性的规则就有kCAFillRuleEvenOdd),
        而EvenOdd 是一个奇偶规则,奇数则显示,偶数则不显示.叠加则是偶数故不显示.
     */
    sharpLayer.fillRule = kCAFillRuleEvenOdd;
    backgroundView.layer.mask = sharpLayer;
    
}