Ios 设备接口定向

如何在应用程序启动时获取当前设备界面方向，即包含应用程序图标的主屏幕方向？ 例如，iPad在屏幕上（

UIDeviceOrientationFaceUp

）设置了我想要的横向界面方向（

UIInterfaceOrientationAndscapeLeft

）。在应用程序启动时，所有界面功能如

• viewController.interfaceOrientation

• [[uiApplication sharedApplication]statusBarOrientation]

---

给出错误的默认值

UIInterfaceOrientationGrait

。存在哪些可能的方式？

接口定向

在调用

didfishLaunchingWithOptions

之前，您可以获得有关方向的良好信息

- (BOOL)application:(UIApplication *)application 
         willFinishLaunchingWithOptions:(NSDictionary *)launchOptions;

在这里，您可以查询UIScreen和UIApplication：

[UIScreen mainScreen].bounds
[UIApplication sharedApplication].statusBarOrientation

这些将根据应用程序启动时的操作系统状态为您提供正确的宽度、高度和界面方向。（在任何情况下，最好避免使用

viewController.interfaceOrientation

，因为它在iOS8中被弃用。）

在你的问题中，你认为StatusBaroOrientation是不正确的，但它在我的iPad mini/8.3上运行良好

设备方向

如果您对设备定向感兴趣，则需要开始侦听设备定向通知。您可以在应用程序中或在视图控制器中委托执行此操作-任何一种方式都不会影响您获得信息的速度，因为设备定向轮询需要时间启动。此外，如果你面朝上/面朝下，你得到的第一个设备方向回调可能是错误的：我认为它只是从接口方向得到了提示

以下是您开始聆听的方式：

[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] 
    addObserver: self 
       selector: @selector(deviceOrientationDidChange:) 
           name: UIDeviceOrientationDidChangeNotification 
         object: nil];

如果在第一次回调之前检查deviceOrientation，它将是未初始化的，因此对您没有多大用处。当你完成这个过程时，你应该停止倾听，因为这个过程会消耗额外的能量

以下是启动序列中的一些日志，iPad面朝上横向放置：

12:44:39.162 [AppDelegate application:willFinishLaunchingWithOptions:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.165 [AppDelegate application:didFinishLaunchingWithOptions:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.179 [ViewController viewDidLoad] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.180 [ViewController viewWillAppear:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.186 [ViewController deviceOrientationDidChange:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationLandscapeRight / 4

12:44:39.204 [ViewController viewDidAppear:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationLandscapeRight / 4

12:44:39.249 [ViewController deviceOrientationDidChange:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationFaceUp / 5

12:44:01.741 [AppDelegate application:willFinishLaunchingWithOptions:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.745 [AppDelegate application:didFinishLaunchingWithOptions:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.758 [ViewController viewDidLoad] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.759 [ViewController viewWillAppear:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.765 [ViewController deviceOrientationDidChange:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationPortrait / 1

12:44:01.784 [ViewController deviceOrientationDidChange:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationFaceUp / 5

12:44:01.828 [ViewController viewDidAppear:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationFaceUp / 5

deviceOrientationDiDChange

的第一次回调发生在启动后约35毫秒。如果设备是平放的，则第一次回调是不正确的-正确的回调在大约20毫秒后发生。这些第一个设备定向通知往往发生在第一个viewController上的

视图将出现

和

视图显示

之间（但这些事件不同步）

相比之下，这是一家iPad面朝上纵向放置的初创公司：

12:44:39.162 [AppDelegate application:willFinishLaunchingWithOptions:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.165 [AppDelegate application:didFinishLaunchingWithOptions:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.179 [ViewController viewDidLoad] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.180 [ViewController viewWillAppear:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationUnknown / 0

12:44:39.186 [ViewController deviceOrientationDidChange:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationLandscapeRight / 4

12:44:39.204 [ViewController viewDidAppear:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationLandscapeRight / 4

12:44:39.249 [ViewController deviceOrientationDidChange:] 
{1024, 768} UIInterfaceOrientationLandscapeLeft / 0 UIDeviceOrientationFaceUp / 5

12:44:01.741 [AppDelegate application:willFinishLaunchingWithOptions:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.745 [AppDelegate application:didFinishLaunchingWithOptions:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.758 [ViewController viewDidLoad] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.759 [ViewController viewWillAppear:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationUnknown / 0

12:44:01.765 [ViewController deviceOrientationDidChange:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationPortrait / 1

12:44:01.784 [ViewController deviceOrientationDidChange:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationFaceUp / 5

12:44:01.828 [ViewController viewDidAppear:] 
{768, 1024} UIInterfaceOrientationPortrait / 2 UIDeviceOrientationFaceUp / 5

伐木

[UIScreen mainScreen].bounds.size 
[UIApplication sharedApplication].statusBarOrientation
[UIDevice currentDevice].orientation

---

使用一些

ENUM

->

NSString

lookup

你所说的“App Strartup”是什么意思？你的意思是在

applicationdifinishloadingwithoptions

中吗？试着读一下这篇文章，我认为它回答了你的问题是的，applicationdifinishloadingwithoptions。这篇文章是错的，至少对我来说是错的。正如我在上面所写的，当面向横向的iPad面朝上放置时，[[UIApplication sharedApplication]statusBarOrientation]返回纵向。感谢您如此详细的描述，现在一切都清楚了！