Q:

Incorrect size of label on viewWillAppear

I have following setup

XIB file which has only landscape view. This view is connection to my controller
There is a label on this view which is connected to IBOutlet UILabel* label
This label is configured like this (it occupies the whole width of screen).

I overrided viewWillAppear and do this (to get the size of label).

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    CGRect rect = _labelTitleLand.frame;
}

The strange thing (which I don't understand). That it returns size = (width 768, height 21) when it launched in portrait (on iPad), which is correct.
And it returns size = (width 741 height 21) when it's launched in landscape. Which is weird. I anticipated that it will return width 1024, height 21 for landscape. 
I was under impression that at the moment of viewWillAppear, all controls sizes are calculated already.
Update 1
If I check labelTitleLand.frame on viewDidAppear then it returns correct results. However, I don't like this, because I want to do some actions (based on this size) which influence how view will be drawn. In the case, if I will do it on viewDidAppear, as I understand there will be visible redrawing.

A:

The layout of the view hierarchy has to be complete before you will get the actual final frames.
So you should check the frame in viewDidLayoutSubviews, which will still be before the view hierarchy is actually drawn. If you need to make changes here you can without causing any redrawing to occur.
viewWillAppear is too early because this is before your autoresizing masks (and/or autolayout constraints) have had their effect.

