How to force view to enter landscape in iOS? - ios

Question

I've see a dozen of possible related questions on SO, but no one seems duplicated:
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My app is a tab-based application.
Currently when entering certain views, I can rotate my phone to landscape to let my view enter landscape.
Main Code:
// In app delegate
- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
if (_allowRotation == YES) {
return UIInterfaceOrientationMaskLandscape;
}
else {
return UIInterfaceOrientationMaskPortrait;
}
}
In views that I want to be landscape, I set allowRotation to YES.
But I want to force views to enter landscape.
In other word, when entering certain views, it automatically enters landscape, no need to rotate phone. Even user locks the screen as portrait. How to achieve this?
I'm using iOS 10.

Answer 1

You have to override the onDidLoad or onDidAppear of the specific view that you want to move it to landscape, for example i added it to viewWillAppear and Disappear:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
self.navigationController.navigationBarHidden = NO;
NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight];
[[UIDevice currentDevice] setValue:value forKey:#"orientation"];
}
-(void)viewWillDisappear:(BOOL)animated {
NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
[[UIDevice currentDevice] setValue:value forKey:#"orientation"];
[super viewWillDisappear:animated];
}
so we the view appear the application move to landscape and when the move disappear it come again to portrait. and for the appDelegate you have to add this:
- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window
{
UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
if ([navigationController.viewControllers.lastObject isKindOfClass:[OpencvViewController class]])
{
return UIInterfaceOrientationMaskLandscape;
}
else
return UIInterfaceOrientationMaskPortrait;
}

Answer 2

Call [UIViewController attemptRotationToDeviceOrientation] when you need rotate orientation
Yours code will be something like that:
appDelegate.allowRotation = YES;
[UIViewController attemptRotationToDeviceOrientation];

Answer 3

Use below code in the specific view controller that you want to rotate in to landscape mode.
-(void)viewDidLayoutSubviews
{
NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:value forKey:#"orientation"];
}

Answer 4

You need to use
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
return UIInterfaceOrientationMaskLandscape;
}
for container view controller in window.rootViewController hierarchy or while presenting view controller over another one.
This enforces you controller to appear in landscape orientation.
The simplest example is assigning rootViewController to the main window.
If you use UIInterfaceOrientationMaskLandscape in your view controller it appears in landscape from the very beginning.
If you try to pack your controller into navigation controller you'll need to subclass the latter to define UIInterfaceOrientationMaskLandscape in it because it is the container for your own view controller.
The same is valid for other containers (e.g. tabBarController or your own containers) which have parent-child link.
While presenting view controller you have also another method to fix orientation:
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation