ios superview and subview

Question

I have a superview and I add a subview to make a selection. In the superview (main view) I do the following: [self.view addSubview:cityViewController.view];

In the cityView, when I have done what I need to do, I just do self.view removeFromSuperView.

The question is, from within the superview, how can I tell when the subview has removed itself.

Answer 1

There's a few ways, but honestly since the current view controller (let's call it main) is just adding the cityViewController's view, keep the handling of adding/removing the views to the current view controller, and just have the main controller call [cityViewController.view removeFromSuperView]

This way you can execute whatever code you want when it receives this notification (be it a method that fires or a UINotification).

-- edit for sample UINotification code --

main.m

...
//Define cityViewController as an iVar and alloc/init it
[[UINotificationCenter defaultCenter] addObserver:self selector:@selector(didFinishView:) name:@"DidFinishView" object:nil];
[self.view addSubview:cityViewController.view];
...

-(void) didFinishView:(NSNotification *)notification {
    [cityViewController.view removeFromSuperView];
}

CityViewController.m

-(IBAction) doneButtonClick:(id) sender {
    [[NSNotificationCenter defaultCenter] postNotificationName:@"DidFinishView" object:nil];
}