Cannot change views in splitviewcontroller

Question

I am trying to change the views in a splitview controller based upon clicking a button in a modalview (a person is selecting an option). I am using notifications to accomplish this:

1. When the button is clicked in the modal view, it issues a notice, then closes (dismisses) itself:

   [[NSNotificationCenter defaultCenter] postNotificationName:@"launchProject" object:nil];

2. The DetailViewController inside the split view controller is listening for this notification, and switches out the views in the SVC

-(void)launchProject:(NSNotification *)notification {
    Project* secondDetail2 = [[Project alloc] initWithNibName:nil bundle:nil];
    ProjectRootController* secondRoot2 = [[ProjectRootController alloc] initWithNibName:nil bundle:nil ]; 
    self.splitViewController.viewControllers =[NSArray arrayWithObjects: secondRoot2, secondDetail2 , nil];

}

I don't understand why the views aren't switching out. Any advice on this will be welcome.

Answer 1

You haven't shown all the code, so I'm guessing the problem is a misunderstanding of how notifications work. It can be initially confusing, but it's very straightforward. So far, you have:

[[NSNotificationCenter defaultCenter] postNotificationName:@"launchProject" object:nil]

which is fine.

But you also need to have

[[NSNotificationCenter defaultCenter]
 addObserver:self 
 selector:@selector(launchProject:) // selector should be your function name, launchProject
 name:@"launchProject" // notification name - must be same as what is given to postNotificatioName.
 object: nil];

somewhere, like in an init function.

In other words, postNotificationName:@"launchProject" does NOT call your function launchProject. It puts a notification with the name "launchProject" into the NSNotificationCenter defaultCenter. If you're not looking for that particular notification, then nothing will happen.

Hope that helps..