iOS: How do I figure out the current orientation in viewWillAppear?

Question

I have a UIWebView that I would like to load different URLs depending on whether its portrait or landscape. How can I figure out what my current orientation is inside viewWillAppear?

Answer 1

Use UIApplication's statusBarOrientation property. You may run into problems if you use the device orientation if it is UIDeviceOrientationFaceUp or UIDeviceOrientationFaceDown.

Example

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if (UIInterfaceOrientationIsLandscape(orientation))
{
   // Do something when in landscape
}
else
{
   // Do something when in portrait
}

Answer 2

UIDeviceOrientation getCurrentOrientation() {
  UIDevice *device = [UIDevice currentDevice];
  [device beginGeneratingDeviceOrientationNotifications];
  UIDeviceOrientation currentOrientation = device.orientation;
  [device endGeneratingDeviceOrientationNotifications];

  return currentOrientation;
}

It's up to you to convert the UIDeviceOrientation to UIInterfaceOrientation.

Answer 3

When the app loads, it does not know its current orientation-

UIInterfaceOrientation orientation = [[UIDevice currentDevice] orientation];
if (orientation == UIDeviceOrientationPortrait) {
    NSLog(@"portrait");// only works after a rotation, not on loading app
}

Once you rotate the device, you get correct orientation, but when the app is loaded, without changing the orientation, it seems that using [[UIDevice currentDevice] orientation] doesn't know the current orientation.

So you need to do 2 things -

1. Try setting the application's accepted device orientations in the plist file
2. In your UIViewControllers, you will need to override the shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation) method to return YES when the app should rotate:

Answer 4

If the is sequencing of relevant calls mean that you can't rely on interfaceOrientation having the correct value at viewWillAppear then — assuming the parent view controller rotates — the safest thing is probably self.parentViewController.interfaceOrientation. Failing that you could try making a first assumption from [[UIDevice currentDevice] orientation], which may not always be 100% on the money (e.g. if the device is lying flat on a table when your app is launched) but is likely to give you a better guess than always assuming portrait.