iOS-UIView specifies rounded corner settings

The rounded corner setting can specify the upper left, lower left, upper right, and lower right corners; single assignment or multiple assignments.

///Set the rounded corners [upper left, upper right corner]
- (void)setCircular{
    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(20,20)];
    //create layer
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
    maskLayer.frame = self.bounds;
    //assign
    maskLayer.path = maskPath.CGPath;
    self.layer.mask = maskLayer;
}