How to implement UIViewController rotation in response to orientation changes?

Question

My app has about 10 different UIViewControllers, just one of which I want to switch to landscape mode if the device is rotated. (All the rest, I want to keep in portrait.)

Answer 1

I do this by having a root view controller (this could be a UITabBarController) and in it's viewDidLoad method i subscribe to rotation events:

[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(didRotate:)
                                                      name:@"UIDeviceOrientationDidChangeNotification" 
                                                      object:nil];

Then in the didRotate: method i look at which view controller is visible when the rotation happened, and what orientation the phone is in:

- (void) didRotate:(NSNotification *)notification { 
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];

/*
    DEVICE JUST ROTATED TO PORTRAIT MODE

 orientation == UIDeviceOrientationFaceUp ||
 orientation == UIDeviceOrientationFaceDown

 */
if(orientation == UIDeviceOrientationPortrait) {





/*
    DEVICE JUST ROTATED TO LANDSCAPE MODE
 */
}else if(orientation == UIInterfaceOrientationLandscapeLeft ||
        orientation == UIInterfaceOrientationLandscapeRight) {






}

}

Within that didRotate: you can look at which is the visible viewController and do what you want from there.

I present a modal view controller in landscape mode when a particular view controller is visible and the phone is rotated into landscape. If any other view controller is visible, i ignore the event.

I force my modal view controller to display in landscape mode in its viewWillAppear method - i can give anyone this code if they want it.

Hope this helps.

Dave