问题
I have a UIViewController instance(viewController1) that I want to lock in landscape mode which I am able to do. On tapping on a button I push another UIViewController(viewController2) which supports both orientations. Now, if user changes the orientation of viewController2 to portrait and goes back to viewController1, viewController1 also changes it's orientation to portrait. How can I avoid that?
Thanks in advance.
回答1:
Add these methods to the view controllers
(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationPortrait); }
Thats for the first
(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES); }
Thats the second
-(BOOL)shouldAutorotateToInterfaceOrientation:UIInterfaceOrientation)toInterfaceOrientation{ if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) { return YES; } return NO; }
回答2:
If those 2 controllers are both implementation of UIViewController both differente classes each other! you can just implement the method shouldAutorotateToInterfaceOrientation, in the first! this should work even when u go back!
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) {
return YES;
}
return NO;}
回答3:
You say push so I assume both ViewControllers are in a NavigationController. If so I'll have to disappoint you, what you want isn't possible. Your rotation callbacks are working correctly, they respond to a rotation, you can't force it. What's happening is the correct behavior.
Best solution is to prevent the user from going back when you're in the orientation the previous ViewController doesn't support, hide the back button for example.
A while back I've made my own NavigationController (doesn't inherit from the UIViewController but it can do exactly the same) and I've tried to implement what you're trying to do. Before pushing or popping, if the view of the ViewController that was about to be shown didn't support the current orientation, I transformed the view of that ViewController by 90° and force the orientation of the status bar to the new ViewController's supported orientation. As soon as the push or pop was complete I'd do a small trick to force the rotation of the device. If you remove the view of the rootViewController from the window and re-add it, the responder chain will be forced to go through all rotation callbacks. When that happened I checked if a ViewController's view was transformed and reset that transformation.
It did work, mostly. But it was messy code and it goes against Apple's current policy that the rootViewController should be responsible of handling the orientation. Also in iOS6 forcing the status bar orientation is guaranteed to work. So I'd really advise against doing this, I've removed this from my own NavigationController too.
来源：https://stackoverflow.com/questions/7125672/uiviewcontroller-orientations