iOS 重置设备方向

Question

考虑以下情况:iPhone 处于纵向模式。我这样做:

NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight];
[[UIDevice currentDevice] setValue:value forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

并将我的设备方向锁定为横向模式。所以我可以向任何方向转动手机，方向保持不变。太棒了；

然后我像这样解锁方向:

NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationUnknown];
[[UIDevice currentDevice] setValue:value forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

并且设备方向将根据需要遵循 iPhone 的物理方向。

现在问题只出现在这种情况下:我将方向设置为横向 (UIInterfaceOrientationLandscapeRight) 并保持手机垂直(纵向模式)。屏幕根据需要旋转。然后我在不移动手机的情况下将方向设置回 UIInterfaceOrientationUnknown...屏幕保持横向，直到我水平转动手机然后回到垂直位置。所以我需要告诉 iPhone，除了解锁方向，将屏幕方向更新为设备物理方向(例如在 Android 中自动发生)。这可能吗？最后:这至少发生在 iPhone 模拟器上。我目前没有可用于测试的真实设备。

Answer 1

您需要订阅方向更改，并在需要时恢复方向。这是完整的示例:

@interface ViewController ()
@property (nonatomic, assign) BOOL fixedOrientation;
@property (nonatomic, assign) UIDeviceOrientation lastOrientation;
@end

@implementation ViewController

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

    self.fixedOrientation = false;
    [UIDevice.currentDevice beginGeneratingDeviceOrientationNotifications];
    [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(deviceOrientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
}

- (void)deviceOrientationChanged:(NSNotification *)notif {
    self.lastOrientation = [UIDevice.currentDevice orientation];
}

- (IBAction)buttPressed {
    UIDeviceOrientation last = [UIDevice.currentDevice orientation];

    NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight];
    [[UIDevice currentDevice] setValue:value forKey:@"orientation"];
    [UIViewController attemptRotationToDeviceOrientation];
    self.fixedOrientation = true;

    self.lastOrientation = last;
}

- (IBAction)butt2Pressed:(id)sender {
    self.fixedOrientation = false;
    NSNumber *value = [NSNumber numberWithInt:self.lastOrientation];
    [[UIDevice currentDevice] setValue:value forKey:@"orientation"];
    [UIViewController attemptRotationToDeviceOrientation];
}

- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    if (self.fixedOrientation) {
        return UIInterfaceOrientationMaskLandscapeRight;
    }
    return UIInterfaceOrientationMaskAll;
}


@end

编辑: iPhone 和 iPad 均应选择 需要全屏 选项才能正常工作，否则 deviceOrientationChanged 将永远不会被调用。