Do we need to call viewWillAppear Manually in TabbarController while tab shifts and navigationController while popping
<p>I am using tabBarController and I want to refresh my views on every tab shift. So if user shifts from tab first to tab fourth and again comes back to first the view must be updated. So do I need to call the viewWillAppear manually as it doesnt call on its own.</p>

<p>Similarly while popping a view from NavigationController I need to call viewWillAppear for the parent view of the view being popped. So again do I need to call it manually.</p>
