iOS开发--切指定圆角的方法

工作中经常需要将一个图形或者控件切为圆角,切为圆形或者四角都切为圆角的方法很常见也很简单,这里着重介绍一下切指定边角为圆角的方法

- (void)viewDidLoad {
    [super viewDidLoad];
    //1.四个角都切为圆角的方法很简单 , 直接:
    UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(20, 100, 100, 100)];
    view1.backgroundColor = [UIColor redColor];
    [self.view addSubview:view1];
    
    view1.layer.cornerRadius = 20.0f;
    view1.layer.masksToBounds = YES;
    
    //2.将指定的几个角切为圆角
    UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(150, 100, 100, 100)];
    view2.backgroundColor = [UIColor blueColor];
    [self.view addSubview:view2];
    
    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view2.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(20, 20)];
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
    maskLayer.frame = view2.bounds;
    maskLayer.path = maskPath.CGPath;
    view2.layer.mask = maskLayer;
    
    //3.将图形切为圆形  只需要将属性 cornerRadius 的值设置为为宽度的一半即可,因为 cornerRadius 属性指的就是半径
    UIView *view3 = [[UIView alloc] initWithFrame:CGRectMake(280, 100, 100, 100)];
    view3.backgroundColor = [UIColor greenColor];
    [self.view addSubview:view3];
    
    view3.layer.cornerRadius = view3.bounds.size.width * 0.5;
    view3.layer.masksToBounds = YES;
    
}

附上效果图: