我想查询iPhone当前的方向。使用
[UIDevice currentDevice].orientation
只要设备没有锁定方向,这个方法就有效。但是如果设备被锁定了,它总是会响应锁定的方向而不是实际设备的方向。
是否有一种高级方法可以获取实际的设备方向?
我想查询iPhone当前的方向。使用
[UIDevice currentDevice].orientation
只要设备没有锁定方向,这个方法就有效。但是如果设备被锁定了,它总是会响应锁定的方向而不是实际设备的方向。
是否有一种高级方法可以获取实际的设备方向?
另外,您可以使用CoreMotion
方向检测算法:
如果abs(y) < abs(x),则您的iPhone处于横向位置,请查看x的符号以检测右侧或左侧
否则,您的iPhone处于纵向位置,请查看y的符号以检测上方或下方。
如果您对正面或反面感兴趣,请查看z的值。
import CoreMotion
var uMM: CMMotionManager!
override func
viewWillAppear( p: Bool ) {
super.viewWillAppear( p )
uMM = CMMotionManager()
uMM.accelerometerUpdateInterval = 0.2
// Using main queue is not recommended. So create new operation queue and pass it to startAccelerometerUpdatesToQueue.
// Dispatch U/I code to main thread using dispach_async in the handler.
uMM.startAccelerometerUpdatesToQueue( NSOperationQueue() ) { p, _ in
if p != nil {
println(
abs( p.acceleration.y ) < abs( p.acceleration.x )
? p.acceleration.x > 0 ? "Right" : "Left"
: p.acceleration.y > 0 ? "Down" : "Up"
)
}
}
}
override func
viewDidDisappear( p: Bool ) {
super.viewDidDisappear( p )
uMM.stopAccelerometerUpdates()
}
这个功能是正确的。如果它总是返回设备方向,即使它被锁定,那么方向改变通知将会触发,这将违背锁定的目的。
回答你的问题,没有办法在不使用私有API的情况下读取加速度计的原始值。
编辑:
经过审核文档后,似乎UIAccelerometer类提供了此数据,即使方向被锁定。这个更改应用于iOS 4及以上版本。即使你可以使用这些数据,你仍然需要对其进行处理以确定方向。这不是一个简单的任务,因为你需要不断监测变化并将它们与旧值进行比较。
此外,请查看此指南以处理运动事件。这可能为您提供另一种确定方向的方法。
将您的视图控制器或任何其他支持UIAccelerometerProtocol的东西设置起来,并开始监听变化(您可以将其设置为10赫兹)。
#define kAccelerometerFrequency 10.0 //Hz
-(void)viewDidAppear:(BOOL)animated {
DLog(@"viewDidAppear");
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
UIAccelerometer* a = [UIAccelerometer sharedAccelerometer];
a.updateInterval = 1 / kAccelerometerFrequency;
a.delegate = self;
}
-(void)viewWillDisappear:(BOOL)animated {
DLog(@"viewWillDisappear");
UIAccelerometer* a = [UIAccelerometer sharedAccelerometer];
a.delegate = nil;
[[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
}
#ifdef DEBUG
+(NSString*)orientationToText:(const UIInterfaceOrientation)ORIENTATION {
switch (ORIENTATION) {
case UIInterfaceOrientationPortrait:
return @"UIInterfaceOrientationPortrait";
case UIInterfaceOrientationPortraitUpsideDown:
return @"UIInterfaceOrientationPortraitUpsideDown";
case UIInterfaceOrientationLandscapeLeft:
return @"UIInterfaceOrientationLandscapeLeft";
case UIInterfaceOrientationLandscapeRight:
return @"UIInterfaceOrientationLandscapeRight";
}
return @"Unknown orientation!";
}
#endif
#pragma mark UIAccelerometerDelegate
-(void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
UIInterfaceOrientation orientationNew;
if (acceleration.x >= 0.75) {
orientationNew = UIInterfaceOrientationLandscapeLeft;
}
else if (acceleration.x <= -0.75) {
orientationNew = UIInterfaceOrientationLandscapeRight;
}
else if (acceleration.y <= -0.75) {
orientationNew = UIInterfaceOrientationPortrait;
}
else if (acceleration.y >= 0.75) {
orientationNew = UIInterfaceOrientationPortraitUpsideDown;
}
else {
// Consider same as last time
return;
}
if (orientationNew == orientationLast)
return;
NSLog(@"Going from %@ to %@!", [[self class] orientationToText:orientationLast], [[self class] orientationToText:orientationNew]);
orientationLast = orientationNew;
}
#pragma mark -
你需要将 UIInterfaceOrientation orientationLast
定义为成员变量,然后你就可以了。
处理所有6个方向
虽然我们通常不关心FaceUp
/ FaceDown
方向,但它们仍然很重要。
考虑到它们可以导致更适当的方向变化灵敏度,而忽略它们可能会导致亚稳态和滞后现象。
这是我处理它们的方法 -
- (void)startMonitoring
{
[self.motionManager startAccelerometerUpdatesToQueue:self.opQueue withHandler:^(CMAccelerometerData * _Nullable accelerometerData, NSError * _Nullable error) {
if (error != nil)
{
NSLog(@"Accelerometer error: %@", error);
}
else
{
float const threshold = 40.0;
BOOL (^isNearValue) (float value1, float value2) = ^BOOL(float value1, float value2)
{
return fabsf(value1 - value2) < threshold;
};
BOOL (^isNearValueABS) (float value1, float value2) = ^BOOL(float value1, float value2)
{
return isNearValue(fabsf(value1), fabsf(value2));
};
float yxAtan = (atan2(accelerometerData.acceleration.y, accelerometerData.acceleration.x)) * 180 / M_PI;
float zyAtan = (atan2(accelerometerData.acceleration.z, accelerometerData.acceleration.y)) * 180 / M_PI;
float zxAtan = (atan2(accelerometerData.acceleration.z, accelerometerData.acceleration.x)) * 180 / M_PI;
UIDeviceOrientation orientation = self.orientation;
if (isNearValue(-90.0, yxAtan) && isNearValueABS(180.0, zyAtan))
{
orientation = UIDeviceOrientationPortrait;
}
else if (isNearValueABS(180.0, yxAtan) && isNearValueABS(180.0, zxAtan))
{
orientation = UIDeviceOrientationLandscapeLeft;
}
else if (isNearValueABS(0.0, yxAtan) && isNearValueABS(0.0, zxAtan))
{
orientation = UIDeviceOrientationLandscapeRight;
}
else if (isNearValue(90.0, yxAtan) && isNearValueABS(0.0, zyAtan))
{
orientation = UIDeviceOrientationPortraitUpsideDown;
}
else if (isNearValue(-90.0, zyAtan) && isNearValue(-90.0, zxAtan))
{
orientation = UIDeviceOrientationFaceUp;
}
else if (isNearValue(90.0, zyAtan) && isNearValue(90.0, zxAtan))
{
orientation = UIDeviceOrientationFaceDown;
}
if (self.orientation != orientation)
{
dispatch_async(dispatch_get_main_queue(), ^{
[self orientationDidChange:orientation];
});
}
}
}];
}
threshold
值设置为40.0(而不是45.0)。这样可以使变化的敏感度降低,防止在拐点处产生迟滞。if (UIDeviceOrientationIsPortrait(orientation) || UIDeviceOrientationIsLandscape(orientation))
{
// Do something
}
当设备方向被锁定时,UIAccelerometer类仍然可以正常工作。您需要自己想出将其变量转换为方向值的方法,但这不应该特别复杂。
可以尝试使用苹果的AccelerometerGraph示例应用程序,查看加速度计在不同方向输出的值。
我使用CoreMotion提供的解决方案,即使设备方向被锁定,也可以正常工作。
let motionManager: CMMotionManager = CMMotionManager()
在 did load 方法中
motionManager.deviceMotionUpdateInterval = 0.01
if motionManager.accelerometerAvailable{
let queue = NSOperationQueue()
motionManager.startAccelerometerUpdatesToQueue(queue, withHandler:
{data, error in
guard let data = data else{
return
}
let angle = (atan2(data.acceleration.y,data.acceleration.x))*180/M_PI;
print(angle)
if(fabs(angle)<=45){
self.orientation = AVCaptureVideoOrientation.LandscapeLeft
print("landscape left")
}else if((fabs(angle)>45)&&(fabs(angle)<135)){
if(angle>0){
self.orientation = AVCaptureVideoOrientation.PortraitUpsideDown
print("portrait upside Down")
}else{
self.orientation = AVCaptureVideoOrientation.Portrait
print("portrait")
}
}else{
self.orientation = AVCaptureVideoOrientation.LandscapeRight
print("landscape right")
}
}
)
} else {
print("Accelerometer is not available")
}
大部分答案使用加速度计,这是总加速度=用户加重力。
但是为了获得设备方向,使用重力加速度更准确。使用重力将防止用户沿特定方向移动的边缘情况发生。要访问重力,我们必须使用startDeviceMotionUpdates
API。
let motionManager = CMMotionManager()
motionManager.startDeviceMotionUpdates(to: OperationQueue()) { (data, error) in
guard let gravity = data?.gravity else { return }
let newDeviceOrientation: UIDeviceOrientation
if abs(gravity.y) < abs(gravity.x) {
newDeviceOrientation = gravity.x > 0 ? .landscapeRight : .landscapeLeft
} else {
newDeviceOrientation = gravity.y > 0 ? .portraitUpsideDown : .portrait
}
}
这里是一个检测设备旋转并返回UIDeviceOrientation的示例。此解决方案使用CoreMotion,在所有情况下都有效。
示例
let orientationManager = APOrientationManager()
orientationManager.delegate = self
/// start detect rotation
orientationManager.startMeasuring()
/// get current interface orientation
let orientation = orientationManager.currentInterfaceOrientation()
print(orientation.rawValue)
/// stop detect rotation
orientationManager.stopMeasuring()
orientationManager.delegate = nil
符合委托
extension ViewController: APOrientationManagerDelegate {
func didChange(deviceOrientation: UIDeviceOrientation) {
/// update UI in main thread
}
}
APOrientationManager.swift
import Foundation
import CoreMotion
import AVFoundation
import UIKit
protocol APOrientationManagerDelegate: class {
func didChange(deviceOrientation: UIDeviceOrientation)
}
class APOrientationManager {
private let motionManager = CMMotionManager()
private let queue = OperationQueue()
private var deviceOrientation: UIDeviceOrientation = .unknown
weak var delegate: APOrientationManagerDelegate?
init() {
motionManager.accelerometerUpdateInterval = 1.0
motionManager.deviceMotionUpdateInterval = 1.0
motionManager.gyroUpdateInterval = 1.0
motionManager.magnetometerUpdateInterval = 1.0
}
func startMeasuring() {
guard motionManager.isDeviceMotionAvailable else {
return
}
motionManager.startAccelerometerUpdates(to: queue) { [weak self] (accelerometerData, error) in
guard let strongSelf = self else {
return
}
guard let accelerometerData = accelerometerData else {
return
}
let acceleration = accelerometerData.acceleration
let xx = -acceleration.x
let yy = acceleration.y
let z = acceleration.z
let angle = atan2(yy, xx)
var deviceOrientation = strongSelf.deviceOrientation
let absoluteZ = fabs(z)
if deviceOrientation == .faceUp || deviceOrientation == .faceDown {
if absoluteZ < 0.845 {
if angle < -2.6 {
deviceOrientation = .landscapeRight
} else if angle > -2.05 && angle < -1.1 {
deviceOrientation = .portrait
} else if angle > -0.48 && angle < 0.48 {
deviceOrientation = .landscapeLeft
} else if angle > 1.08 && angle < 2.08 {
deviceOrientation = .portraitUpsideDown
}
} else if z < 0 {
deviceOrientation = .faceUp
} else if z > 0 {
deviceOrientation = .faceDown
}
} else {
if z > 0.875 {
deviceOrientation = .faceDown
} else if z < -0.875 {
deviceOrientation = .faceUp
} else {
switch deviceOrientation {
case .landscapeLeft:
if angle < -1.07 {
deviceOrientation = .portrait
}
if angle > 1.08 {
deviceOrientation = .portraitUpsideDown
}
case .landscapeRight:
if angle < 0 && angle > -2.05 {
deviceOrientation = .portrait
}
if angle > 0 && angle < 2.05 {
deviceOrientation = .portraitUpsideDown
}
case .portraitUpsideDown:
if angle > 2.66 {
deviceOrientation = .landscapeRight
}
if angle < 0.48 {
deviceOrientation = .landscapeLeft
}
case .portrait:
if angle > -0.47 {
deviceOrientation = .landscapeLeft
}
if angle < -2.64 {
deviceOrientation = .landscapeRight
}
default:
if angle > -0.47 {
deviceOrientation = .landscapeLeft
}
if angle < -2.64 {
deviceOrientation = .landscapeRight
}
}
}
}
if strongSelf.deviceOrientation != deviceOrientation {
strongSelf.deviceOrientation = deviceOrientation
strongSelf.delegate?.didChange(deviceOrientation: deviceOrientation)
}
}
}
func stopMeasuring() {
motionManager.stopAccelerometerUpdates()
}
func currentInterfaceOrientation() -> AVCaptureVideoOrientation {
switch deviceOrientation {
case .portrait:
return .portrait
case .landscapeRight:
return .landscapeLeft
case .landscapeLeft:
return .landscapeRight
case .portraitUpsideDown:
return .portraitUpsideDown
default:
return .portrait
}
}
}
在这里使用Satachito的优秀答案,以下是代码,还可以检测设备是否面朝上或面朝下
import CoreMotion
var mm: CMMotionManager!
init() {
self.mm = CMMotionManager()
self.mm.accelerometerUpdateInterval = 0.2
}
public func startOrientationUpdates() {
// Using main queue is not recommended. So create new operation queue and pass it to startAccelerometerUpdatesToQueue.
// Dispatch U/I code to main thread using dispach_async in the handler.
self.mm.startAccelerometerUpdates( to: OperationQueue() ) { p, _ in
if let p = p {
if(p.acceleration.x > -0.3 && p.acceleration.x < 0.3 && p.acceleration.z < -0.95) {
print("face up")
}
else if(p.acceleration.x > -0.3 && p.acceleration.x < 0.3 && p.acceleration.z > 0.95) {
print("face down")
}
else {
print(
abs( p.acceleration.y ) < abs( p.acceleration.x )
? p.acceleration.x > 0 ? "Right" : "Left"
: p.acceleration.y > 0 ? "Down" : "Up"
)
}
}
}
}
public func endOrientationUpdates() {
self.mm.stopAccelerometerUpdates()
}
CMMotionManager
可能会有所帮助,但不是上述方法。上述逻辑不稳定。我已经进行了彻底的测试,并发现通过查看acceleration.x/y/z
的值不能帮助确定方向。float angle = (atan2(accelerometerData.acceleration.y,accelerometerData.acceleration.x))*180/M_PI;
而对于方向,
if(fabs(angle<=45)currOrientation=UIDeviceOrientationLandscapeRight;
else if((fabs(angle)>45)&&(fabs(angle)<135))currOrientation=((angle>0)?UIDeviceOrientationPortraitUpsideDown:UIDeviceOrientationPortrait);
else currOrientation = UIDeviceOrientationLandscapeLeft;
这可能对某些人很方便,尽管这并不能帮助我找到另外两个方向,即UIDeviceOrientationFaceUp
和UIDeviceOrientationFaceDown
。