解雇键盘后如何恢复UIInputViewController self.view？

Question

I'm developing an application that has an Keyboard extension, At some uses of the Keyboard extension (for example: when I use the switch keyboard button) the extension is going through the viewDidDisappear and at this case I know I can clean the keyboard and it's getting deallocated with all it's views and the memory is freed. At other uses (for example: when using the Notes application and pressing the Done/Back button) the extension is going through the viewWillDisappear but not through the viewDidDisappear , So in this case I'm not cleaning the Keyboard as it's not reaching my cleaning methods and therefore it's not getting deallocated.

At this point I would expect that when I return to the keyboard by going back to the note for example I would receive the previous UIInputViewController with the view I already built.

Unfortunately at this point the isViewLoaded() method returns false and my UIInputViewController is going again through the loadView method therefore building again all the views all over again, as a result the application memory grows until at some point I reach the nasty didReceiveMemoryWarning method callback.

I would like to restore somehow the view I created for my keyboard in the UIInputViewController that was initialized first. Does some one know is it possible and how could this be achieved?

I was looking into the restorationIdentifier to accomplish this task, correct me if I'm wrong but this is used with an ordinary UIViewController and can't be used with the UIInputViewController as not my AppDelegate is responsible to launch it.

Update

From further research I made, I came to a conclusion that no matter what the operation you commit:

1. Use Done/Back button in the Notes application.
2. Switch to the Messages app and use the keyboard there.
3. Use the “switch keyboard" button

And other scenarios, the UIInputViewController class always goes through the init method .

From my understanding of the object oriented programming this mean that whoever calls my keyboard to reaper does it using the constructor and basically creates a new instance of the keyboard. That means that I will never have an available view on first reappearance of the keyboard in any of the behaviors and I always have to build the keyboard view for the new instance and cleanup the old one. Is this right? or there is a way to presereve the view of the UIInputViewController?

Answer 1

Unless you're using your own custom application with the keyboard to store its previous instance, there's no way to do this. In everything besides a custom application designed by you, it is beyond your scope