Why does adding a top border to a subview does not resize with auto layout/device rotation? - objective-c

Question

(using Xcode 6 and iOS 8)
How can I create a top border in a sub UIView that sizes correctly when the view changes due to auto layout or device rotation?
I have code draws a line as the top border but it uses the size of what I have in Interface Builder. It does not size correctly after auto layout resizes the view nor after device rotation.
In the UIViewController, I tried [self.view layoutSubviews], [self.view layoutIfNeeded], [self.myCustomView layoutIfNeeded], and so on, in following method because when this method is called, the view has been resized by auto layout. But doesn't change the size of the line.
UIViewController:
- (void) viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
[self.myCustomView layoutIfNeeded];
}
Hierarchy is:
UIViewController -> ViewController's View -> my custom UIView
Tried 2 different methods to draw the border which do draw the lines in my-custom-uiview. Neither one is recalled after the view is resized by auto layout or device rotation. This really shouldn't be that hard!
myCustomUIView:
First method:
// in initWithCoder, initWithFrame, awakeFromNib methods
CALayer *border = [CALayer layer];
border.frame = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.size.width, 2.0f);
border.backgroundColor = [UIColor blackColor].CGColor;
[self.contentView.layer addSublayer:border];
Second method:
- (void) drawRect:(CGRect)rect {
UIBezierPath *line = [UIBezierPath bezierPath];
[line moveToPoint:CGPointMake(0, 0)];
[line addLineToPoint:CGPointMake(self.bounds.size.width, 0)];
[line setLineWidth:2.0f];
[[UIColor blackColor] setStroke];
[line stroke];
}