我有一个关于如何在 iOS 上检测设备方向的问题。我不需要接收更改通知，只需要接收当前方向本身。这似乎是一个相当简单的问题，但我一直无法理解它。以下是我到目前为止所做的：
UIDevice *myDevice = [UIDevice currentDevice] ;
[myDevice beginGeneratingDeviceOrientationNotifications];
UIDeviceOrientation deviceOrientation = myDevice.orientation;
BOOL isCurrentlyLandscapeView = UIDeviceOrientationIsLandscape(deviceOrientation);
[myDevice endGeneratingDeviceOrientationNotifications];
在我看来，这应该有效。我让设备接收设备方向通知，然后询问它的方向，但它不工作，我不知道为什么。
真正的老线程，但没有真正的解决方案。
我有同样的问题，但发现获取 UIDeviceOrientation 并不总是一致的，所以改用这个：
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if(orientation == 0) //Default orientation
//UI is in Default (Portrait) -- this is really a just a failsafe.
else if(orientation == UIInterfaceOrientationPortrait)
//Do something if the orientation is in Portrait
else if(orientation == UIInterfaceOrientationLandscapeLeft)
// Do something if Left
else if(orientation == UIInterfaceOrientationLandscapeRight)
//Do something if right
如果 UIViewController：
if (UIDeviceOrientationIsLandscape(self.interfaceOrientation))
{
//
}
如果 UIView：
if (UIDeviceOrientationIsLandscape([UIApplication sharedApplication].statusBarOrientation))
{
//
}
UIDevice.h：
#define UIDeviceOrientationIsPortrait(orientation) ((orientation) == UIDeviceOrientationPortrait || (orientation) == UIDeviceOrientationPortraitUpsideDown)
#define UIDeviceOrientationIsLandscape(orientation) ((orientation) == UIDeviceOrientationLandscapeLeft || (orientation) == UIDeviceOrientationLandscapeRight)
更新：
将此代码添加到 xxx-Prefix.pch 然后您可以在任何地方使用它：
// check device orientation
#define dDeviceOrientation [[UIDevice currentDevice] orientation]
#define isPortrait UIDeviceOrientationIsPortrait(dDeviceOrientation)
#define isLandscape UIDeviceOrientationIsLandscape(dDeviceOrientation)
#define isFaceUp dDeviceOrientation == UIDeviceOrientationFaceUp ? YES : NO
#define isFaceDown dDeviceOrientation == UIDeviceOrientationFaceDown ? YES : NO
用法：
if (isLandscape) { NSLog(@"Landscape"); }
对于您首先要寻找的内容，如果方向改变，您必须获得通知！你可以在 viewDidLoad 中设置这个东西，比如
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(OrientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
并且每当您的设备的方向发生变化时，都会调用OrientationDidChange，您可以根据方向做任何您想做的事情
-(void)OrientationDidChange:(NSNotification*)notification
{
UIDeviceOrientation Orientation=[[UIDevice currentDevice]orientation];
if(Orientation==UIDeviceOrientationLandscapeLeft || Orientation==UIDeviceOrientationLandscapeRight)
{
}
else if(Orientation==UIDeviceOrientationPortrait)
{
}
}
如果您想直接从加速度计获取设备方向[[UIDevice currentDevice] orientation]，请使用. 但是，如果您需要应用程序的当前方向（界面方向），请使用[[UIApplication sharedApplication] statusBarOrientation].
UIViewController有一个interfaceOrientation属性，你可以访问它来找出视图控制器的当前方向。
至于你的例子，那应该有效。当你说它不起作用时，你是什么意思？它给你的结果与你的预期相比是什么？
在 Swift 3.0 中
获取设备方向。
/* return current device orientation.
This will return UIDeviceOrientationUnknown unless device orientation notifications are being generated.
*/
UIDevice.current.orientation
从您的应用程序获取设备方向
UIApplication.shared.statusBarOrientation
对"UIDeviceOrientation"不满意，因为当 UIViewcontroller 方向固定到特定方向时，您不会获得与设备方向相关的信息，因此正确的做法是使用"UIInterfaceOrientation"。
您可以使用"self.interfaceOrientation"从 UIViewController 获取方向，但是当您分解我们的代码时，您可能需要在视图控制器（自定义视图、类别...）之外进行这种测试，所以您仍然可以使用rootviewController访问控制器之外的任何地方的信息：
if (UIInterfaceOrientationIsLandscape(view.window.rootViewController.interfaceOrientation)) {
}
无论是否启用方向锁定，都有一种方法可以通过使用来自 CoreMotion 的数据来实现。这是代码：
#import <CoreMotion/CoreMotion.h>
CMMotionManager *cm=[[CMMotionManager alloc] init];
cm.deviceMotionUpdateInterval=0.2f;
[cm startDeviceMotionUpdatesToQueue:[NSOperationQueue mainQueue]
withHandler:^(CMDeviceMotion *data, NSError *error) {
if(fabs(data.gravity.x)>fabs(data.gravity.y)){
NSLog(@"LANSCAPE");
if(data.gravity.x>=0){
NSLog(@"LEFT");
}
else{
NSLog(@"RIGHT");
}
}
else{
NSLog(@"PORTRAIT");
if(data.gravity.y>=0){
NSLog(@"DOWN");
}
else{
NSLog(@"UP");
}
}
}];
您是否为设备方向解锁了硬件锁？我的 iPad 1 边缘有一个。
这里有一些 Swift 变量可以让检测更容易：
let LANDSCAPE_RIGHT: Bool = UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeRight
let LANDSCAPE_LEFT: Bool = UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeLeft
let LANDSCAPE: Bool = LANDSCAPE_LEFT || LANDSCAPE_RIGHT
let PORTRAIT_NORMAL: Bool = UIDevice.currentDevice().orientation == UIDeviceOrientation.Portrait
let PORTRAIT_REVERSE: Bool = UIDevice.currentDevice().orientation == UIDeviceOrientation.PortraitUpsideDown
let PORTRAIT: Bool = PORTRAIT_REVERSE || PORTRAIT_NORMAL
使用此功能。
func deviceOrientation() -> String! {
let device = UIDevice.current
if device.isGeneratingDeviceOrientationNotifications {
device.beginGeneratingDeviceOrientationNotifications()
var deviceOrientation: String
let deviceOrientationRaw = device.orientation.rawValue
switch deviceOrientationRaw {
case 1:
deviceOrientation = "Portrait"
case 2:
deviceOrientation = "Upside Down"
case 3:
deviceOrientation = "Landscape Right"
case 4:
deviceOrientation = "Landscape Left"
case 5:
deviceOrientation = "Camera Facing Down"
case 6:
deviceOrientation = "Camera Facing Up"
default:
deviceOrientation = "Unknown"
}
return deviceOrientation
} else {
return nil
}
}
我目前这样做的方式：
+ (BOOL)isPortrait {
let window = UIApplication.sharedApplication.delegate.window;
if(window.rootViewController) {
let orientation =
window.rootViewController.interfaceOrientation;
return UIInterfaceOrientationIsPortrait(orientation);
} else {
let orientation =
UIApplication.sharedApplication.statusBarOrientation;
return UIInterfaceOrientationIsPortrait(orientation);
}
}
如果由于某种原因没有 rootViewController 对 statusBarOrientation 不安全...
以及 swift 中最可靠的方法：
public extension UIScreen {
public class var isPortrait: Bool {
UIApplication.shared.delegate?.window??.rootViewController?.interfaceOrientation.isPortrait ??
UIApplication.shared.statusBarOrientation.isPortrait
}
public class var isLandscape: Bool { !isPortrait }
}
这是我使用 Combine 的解决方案，它很容易与 SwiftUI 或常规 Swift Object 一起使用。对于这种真正的全局对象，单例对象（静态实例）比“环境”要好。
// Singleton object to keep the interface orientation (and any other global state)
class SceneContext: ObservableObject {
@Published var interfaceOrientation = UIInterfaceOrientation.portrait
static let shared = SceneContext()
}
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
...
func windowScene(_ windowScene: UIWindowScene, didUpdate previousCoordinateSpace: UICoordinateSpace, interfaceOrientation previousInterfaceOrientation: UIInterfaceOrientation, traitCollection previousTraitCollection: UITraitCollection) {
SceneContext.shared.interfaceOrientation = windowScene.interfaceOrientation
}
}
// if you want to execute some code whenever the orientation changes in SwiftUI
someView {
....
}
.onReceive(SceneContext.shared.$interfaceOrientation) { (orientation) in
// do something with the new orientation
}
// if you want to execute some code whenever the orientation changes in a regular Swift object
let pub = SceneContext.shared.$interfaceOrientation.sink(receiveValue: { (orientation) in
// do something with the new orientation
...
})