viewWillAppear: method doesn't seem to respond while using tab bar and navigation controllers together

Question

I am using Tab bar + navigation based application and I have 4 tab bars. When I navigate from one view controller to another view controller, the viewWillAppear: method doesn't seem to respond and I am being forced to call it manually by creating the object of the next view controller. So my question is, how do I avoid calling the viewWillAppear: method manually whenever I navigate from one view controller to another? Instead, it should get triggered automatically just like the viewdidLoad: method gets triggered when you navigate from one view controller to other. Please guide me on how could I do that.

Hoping for the best possible Answer Thanks in Advance

Answer 1

You are correct, viewWillAppear is a little special, it is usually called automatically but in some cases including when you are adding a view controllers view manually (view addSubview:), and also when adding this as a view controller to a UITabBarController or UINavigationCnotroller (of which you have both !) it doesn't get messaged.

This however is only for the root view, as you navigate (maybe with a navigation controller) back and forth, that root view's viewWillAppear will get triggered as some point.

In short, if you need to implement something in viewWillAppear in these cases, you should message it yourself when you know it's going to be presented. You can handle this case in your view controller, check out the following article about the matter:

http://www.touchthatfruit.com/viewwillappear-and-viewdidappear-not-being-ca

Good luck.