View的圆角

UIBezierPath* rounded = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, ScreenWidth, ScreenHeight*3/4) byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(10.0f, 10.0f)];

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

        [shape setPath:rounded.CGPath];

        self.layer.mask = shape;