How to use UIBezierPath in a auto layout view? - objective-c

Question

As far as I know, views displayed by constraints don't got a frame, so what should I do when I want to draw some lines in these views? Methods like moveToPoint do need a CGRect.
Here's my check: NSLog(#"%f,%f,%f,%f",self.contentView.frame.origin.x,self.contentView.frame.origin.y,self.contentView.frame.size.width,self.contentView.frame.size.height);
And the result is 0.000000,0.000000,0.000000,0.000000
For more details, here's my code:
-(void)loadView
{
self.view = [[UIView alloc]init];
self.titleView = [[UIView alloc]init];
self.placesHolder = [[UIView alloc]init];
self.contentView = [[UIView alloc]init];
self.titleView.translatesAutoresizingMaskIntoConstraints = NO;
self.placesHolder.translatesAutoresizingMaskIntoConstraints = NO;
self.contentView.translatesAutoresizingMaskIntoConstraints = NO;
self.titleView.backgroundColor = [UIColor grayColor];
self.placesHolder.backgroundColor = [UIColor blueColor];
self.contentView.backgroundColor = [UIColor redColor];
[self.view addSubview:self.titleView];
[self.view addSubview:self.placesHolder];
[self.view addSubview:self.contentView];
NSDictionary *timeLineViewMap = #{#"titleView":self.titleView,
#"placesHolder":self.placesHolder,
#"contentView":self.contentView
};
NSArray *titleHorizon = [NSLayoutConstraint constraintsWithVisualFormat:#"H:|[titleView]|" options:0 metrics:nil views:timeLineViewMap];
NSArray *placesHolderHorizon = [NSLayoutConstraint constraintsWithVisualFormat:#"H:|[placesHolder(==58)]-0-[contentView]|" options:0 metrics:nil views:timeLineViewMap];
NSArray *titleVertical = [NSLayoutConstraint constraintsWithVisualFormat:#"V:|[titleView(==58)]-0-[placesHolder]|" options:0 metrics:nil views:timeLineViewMap];
NSArray *contentViewConstrain = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[titleView]-0-[contentView]|" options:0 metrics:nil views:timeLineViewMap];
[self.view addConstraints:titleHorizon];
[self.view addConstraints:placesHolderHorizon];
[self.view addConstraints:titleVertical];
[self.view addConstraints:contentViewConstrain];
}

Answer 1

Of course UIView does have a frame even with AutoLayout. You just don't set the values manually, AutoLayout is doing that for you. Methods like setFrame: are still called. Simply implement drawRect: like you always did.

Answer 2

Well, problem kind of solved, it seems that a frame of a view don't get a size until it's on the viewDidAppear move. Then I checked some other questions like iOS AutoLayout - get frame size width, which indicate that addConstraints should be put in the viewDidLayoutSubviews method, which is not in the viewController life cycle.