ios - How can I save an array of another view controller to the file within the app delegate? -

My root view controller has an array that I want to save (using core data) whenever applicationDidEnterBackground

How can I send a message to an example of the Root View Controller in the delegate?

I have set the representative as the root, when the controller was thinking about giving a reference to see, but it seems ineligible, is there a better way to do this?

1) In your RootViewController .h file,

  + ( RootViewController *) Shared Store;   
 2) In your RootViewController .m file,  
  + (RootViewController *) shared store {Static RootviewController * myStore = Zero; If (! Mystore) {myStore = [[rootweek controller alloc] init]; } My return return; }   
 3) Go to your AppDelegate.m file and import your RootViewController  
  #import RootViewController.h   < P> 4) In your AppDelegate.m file, go to the ApplicationDidEnterBackground method and type:  
  [[RootviewControler ShareStore] saveChanges]; 5) Apply the SaveChanges method in RootViewController.