[英]How Do I detect the orientation of the device on iOS?
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,但我一直无法解决它。 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。 我使设备能够接收设备方向通知,然后询问它所处的方向,但它不起作用,我不知道为什么。
真的很老的线程,但没有真正的解决方案。
我遇到了同样的问题,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 然后你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
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(OrientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
并且每当您的设备的方向改变OrientationDidChange调用时,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,请使用[[UIDevice currentDevice] orientation]
。 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,您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? 与您的预期相比,它给了您什么结果?
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 方向固定为特定方向时,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之外进行此类测试(自定义视图、类别...),因此您仍然可以使用rootviewController访问控制器之外的任何位置的信息:
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 的数据来实现这一点。 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");
}
}
}];
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
您是否已解锁设备方向的硬件锁? 我的 iPad 1 边缘有一个。
我目前的做法是:
+ (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 还没有安全到 statusBarOrientation ...
以及 swift 中最好的可靠方法:
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”更好。
// 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
...
})
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
}
}
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