如何在设备旋转过程中“锁定”视图的方向

Question

比方说，我有一个视图控制器，称之为ViewControllerPortrait，它被设计为只能在肖像模式下显示。例如： -

当用户旋转设备的风景，我不想ViewControllerPortrait永远重新定位自己的风景，但我想提出一个新的全屏视图。我们称之为全屏视图控制器ViewControllerLandscapeFull。例如：

我再也不想看到的是这样的：

我试图做到这一点的方法是让窗口的RootViewController的存在ViewControllerLandscapeFull在当屏幕全屏时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]; 

然后在ViewControllerLandscapeFull我：

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

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

这工作得相当好。由于ViewControllerLandscapeFull“更喜欢”风景，并具有UIModalPresentationFullScreenmodalPresentationStyle，它只能在风景中显示。通过为supportedInterfaceOrientations返回landscape | portrait，设备旋转回肖像被允许发生ViewControllerLandscapeFull得到willRotateToInterfaceOrientation:duration:并最终调用dismissViewControllerAnimated:NO。

我唯一的问题是，在旋转回肖像期间，您可以暂时看到横向的ViewControllerPortrait，这就是我想要避免的。

ViewControllerPortrait确实实现：

- (NSUInteger)supportedInterfaceOrientations 
{ 
    return UIInterfaceOrientationMaskPortrait; 
} 

而且我验证过的UIKit是调用它，但它似乎没有任何效果。 （该文档说，supportedInterfaceOrientations只在根视图控制器和视图控制器呈现全屏，所以我实际上很惊讶UIKit称之为。）

FWIW，我正在与iOS 8 beta 5 SDK并建设7/8。

Muchas gracias。

Answer 1

我刚刚开始使用iPhone编程，但也许这将工作...

点击您的项目文件>部署信息。然后，除了肖像以外，请取消选中所有内容这样旋转设备将不会重新定位自己。

但是，你仍然可以测试设备是否旋转或不符合本：

- (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 

上述方法不会被调用一个视图 - 控制的，如果他们是navigationcontroller的任何tabbarcontroller内。如果这些方法在tabbarcontroller或导航控制器内部声明，那么它们将被调用。在我的例子中，viewcontrollers在navigationcontroller里面，导航控制器在tabbarcontroller里面。

为了解决这个我做一个类FixedOrientationTab，它是UITabBarController一个子类，导航类OrientationEnabledNavigation，它是UINavigationController一个子类。然后我在FixedOrientationTab和OrientationEnabledNavigation内实施shouldAutorotate,supportedInterfaceOrientations,preferredInterfaceOrientationForPresentation方法。

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 

然后，如果你想在你的项目中使用导航控制器，然后使用OrientationEnabledNavigation和的TabBar FixedOrientationTab。之后，如果您在viewcontroller中执行shouldAutorotate，supportedInterfaceOrientations，preferredInterfaceOrientationForPresentation这些方法，那么它们将被调用。

希望这会有所帮助.. :)