在设备旋转期间如何“锁定”视图的方向

Question

Let's say I have a view controller, call it ViewControllerPortrait, which is designed to display in portrait mode only. Eg:

When the user rotates the device to landscape, I don't want ViewControllerPortrait to ever re-orient itself to landscape, but I do want to present a new full-screen view. Let's call the full-screen view controller ViewControllerLandscapeFull. Eg:

What I don't ever want to see is this:

The way I tried to do this is to have the window's rootViewController present ViewControllerLandscapeFull in full screen when it gets a willRotateToInterfaceOrientation:duration:

[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];
[navigationViewController setNavigationBarHidden:YES animated:YES];

self.viewControllerPortrait = [[ViewControllerPortrait alloc] init];
self.viewControllerPortrait.modalPresentationStyle = UIModalPresentationFullScreen;
[self presentViewController:self.viewControllerPortrait animated:NO completion:NULL];

And then in ViewControllerLandscapeFull I have:

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskLandscape | UIInterfaceOrientationMaskPortrait;
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return (UIInterfaceOrientation)[UIDevice currentDevice].orientation;
}

This works fairly well. Since ViewControllerLandscapeFull "prefers" landscape and has a UIModalPresentationFullScreen modalPresentationStyle , it only ever shows in landscape. By returning landscape | portrait landscape | portrait for supportedInterfaceOrientations, device rotations back to portrait are allowed which happens when ViewControllerLandscapeFull gets willRotateToInterfaceOrientation:duration: and eventually dismissViewControllerAnimated:NO is called on it.

The only problem I have is that during the rotation back to portrait, you can momentarily see ViewControllerPortrait in landscape orientation, and that's what I'm trying to avoid.

ViewControllerPortrait does implement:

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskPortrait;
}

And I've verified that UIKit is calling it but it apparently has no effect. (The docs say that supportedInterfaceOrientations is only called on root view controllers and view controllers presented full screen, so I'm actually surprised UIKit calls it at all.)

FWIW, I'm working with the iOS 8 beta 5 SDK and building for 7/8.

Muchas gracias.

Answer 1

I'm just beginning programming with iPhones, but maybe this will work...

Click on your project file > deployment info. Then unclick everything except portrait. This way rotating the device won't reorientate itself.

However, you can still test whether the device rotates or not with this:

- (BOOL)shouldAutorotate
{
    if (UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation))
    {
         NSLog(@"ROTATE to landscape");
         kitty.hidden = NO; 
         //(kitty is my imageview, hidden on load), once the device rotates to landscape, you can show your image.(or you can do something else)
    }
    else{
        NSLog(@"ROTATE to portrait");
        kitty.hidden = YES;
    }
    return YES;
}

Answer 2

houldAutorotate, supportedInterfaceOrientations, preferredInterfaceOrientationForPresentation

The above methods don't get called of a viewcontroller if they are inside any tabbarcontroller of navigationcontroller. If these methods are declared inside tabbarcontroller or navigation controller then they will get called. In my case the viewcontrollers was inside navigationcontroller and the navigation controllers are inside a tabbarcontroller.

For solving this I make a class FixedOrientationTab , it is a subclass of UITabBarController , and a navigation class OrientationEnabledNavigation , it is a subclass of UINavigationController . Then I implemented shouldAutorotate , supportedInterfaceOrientations , preferredInterfaceOrientationForPresentation methods inside FixedOrientationTab and OrientationEnabledNavigation .

OrientationEnabledNavigation.h

#import <UIKit/UIKit.h>

@interface OrientationEnabledNavigation : UINavigationController

@end

OrientationEnabledNavigation.m

#import "OrientationEnabledNavigation.h"

@interface OrientationEnabledNavigation ()

@end

@implementation OrientationEnabledNavigation

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (BOOL)shouldAutorotate
{
    return [self.topViewController shouldAutorotate];
//    return NO;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return [self.topViewController supportedInterfaceOrientations];
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return [self.topViewController preferredInterfaceOrientationForPresentation];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

FixedOrientationTab.h

#import <UIKit/UIKit.h>

@interface FixedOrientationTab : UITabBarController

@end

FixedOrientationTab.m

#import "FixedOrientationTab.h"

@interface FixedOrientationTab ()

@end

@implementation FixedOrientationTab

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (BOOL)shouldAutorotate
{
    return [self.selectedViewController shouldAutorotate];
    //    return NO;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return [self.selectedViewController supportedInterfaceOrientations];
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return [self.selectedViewController preferredInterfaceOrientationForPresentation];
}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Then if you want to use navigation controller in your project then use OrientationEnabledNavigation and for tabbar FixedOrientationTab . After that if you implement shouldAutorotate , supportedInterfaceOrientations , preferredInterfaceOrientationForPresentation these method inside your viewcontroller then they will get called.

Hope this helps.. :)