UIview 設置指定的幾個角爲圓角

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(120,10,80,80)];

view.backgroundColor = [UIColor redColor];[self.view addSubview:view2];

UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view2.bounds 

byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(10, 10)];

CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];

maskLayer.frame = view.bounds;

maskLayer.path = maskPath.CGPath;

view.layer.mask = maskLayer;

指定了需要成爲圓角的角。該參數是UIRectCorner類型的，可選的值有：

* UIRectCornerTopLeft

* UIRectCornerTopRight

* UIRectCornerBottomLeft

* UIRectCornerBottomRight

* UIRectCornerAllCorners