在被遮挡时激活接近监测以关闭iphone屏幕

Question

需要

当用户将iphone倒置在q桌上时，我想关闭屏幕。同时，我不想一直启用接近监视器，因为这对用户来说非常不舒服，而且很多时候会错过点火，这取决于你如何抓住设备。

什么是

这是为了在晚上离开，在运行应用程序的同时节省电池和屏幕寿命。

解决方法

我正在考虑的是使用加速度计来确定面部是否向下，如果是，则激活接近审查器。简单的东西。。。

问题

在实践中，该解决方案不起作用，它表明，如果审查程序在您激活时被"屏蔽"，它将不会注册其当前状态。

刷新UIDevice一些方法？

我在使用什么

-(id)init {
    if ((self = [super init])) 
    {
        NSLog(@"Init ShakerAnalizer");
        accelerometer = [UIAccelerometer sharedAccelerometer];
        accelerometer.delegate = self;
        accelerometer.updateInterval = 5.0f;
    }
    return self;
}
-(void)accelerometer:(UIAccelerometer *)accel didAccelerate:(UIAcceleration *)acceleration
{
    if (accelerometer) 
    {        
        NSLog(@"Accelerometer Z:::  %f", acceleration.z);
        if (acceleration.z > kFlippedThreshold) 
            device.proximityMonitoringEnabled = YES;
        else
            device.proximityMonitoringEnabled = NO;
    }
}

Answer 1

您不希望监视翻转事件本身；相反，您希望观察被翻转的状态。

这里有一个完整的实现，在这个实现中，您只需在需要的时候（可能一直都是，也可能不是）调用monitorForFaceDownOnSurfaceStatus:，并填写setFaceDownOnSurface:来处理该状态（可能像我的示例中那样将屏幕亮度设置为最小值）：

- (BOOL)canEnableProximityMonitoring
{
    UIDevice *device = [UIDevice currentDevice];
    BOOL wasEnabled = device.proximityMonitoringEnabled;
    BOOL could;
    device.proximityMonitoringEnabled = YES;
    could = device.proximityMonitoringEnabled;
    device.proximityMonitoringEnabled = wasEnabled;
    return could;
}
BOOL isMonitoringForFaceDown = NO;
- (void)monitorForFaceDownOnSurfaceStatus:(BOOL)shouldMonitor
{
    if ( ![self canEnableProximityMonitoring] ) {
        return;
    }
    UIDevice *device = [UIDevice currentDevice];
    if ( shouldMonitor ) {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceOrientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
        [device beginGeneratingDeviceOrientationNotifications];
    } else {
        [device endGeneratingDeviceOrientationNotifications];
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UIDeviceOrientationDidChangeNotification object:nil];
    }
    if ( isMonitoringForFaceDown != shouldMonitor ) {
        isMonitoringForFaceDown = shouldMonitor;
        [self deviceOrientationChanged:nil];
    }
}
UIDeviceOrientation oldOrientation = UIDeviceOrientationUnknown;
- (void)deviceOrientationChanged:(NSNotification *)note
{
    if ( !note ) {
        [self monitorProximityState:NO];
        return;
    }
    UIDevice *device = [UIDevice currentDevice];
    UIDeviceOrientation newOrientation = device.orientation;
    if ( newOrientation != oldOrientation ) {
        oldOrientation = newOrientation;
        [self monitorProximityState:(oldOrientation == UIDeviceOrientationFaceDown)];
    }
}
BOOL isMonitoringProximity = NO;
- (void)monitorProximityState:(BOOL)shouldMonitor
{   
    UIDevice *device = [UIDevice currentDevice];
    if ( shouldMonitor ) {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(proximityStateChanged:) name:UIDeviceProximityStateDidChangeNotification object:nil];
        device.proximityMonitoringEnabled = YES;
    } else {
        device.proximityMonitoringEnabled = NO;
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UIDeviceProximityStateDidChangeNotification object:nil];
    }
    if ( isMonitoringProximity != shouldMonitor ) {
        isMonitoringProximity = shouldMonitor;
        [self proximityStateChanged:nil];
    }
}
BOOL oldProximityState = NO;
- (void)proximityStateChanged:(NSNotification *)note
{
    if ( !note ) {
        [self setFaceDownOnSurface:NO];
        return;
    }
    UIDevice *device = [UIDevice currentDevice];
    BOOL newProximityState = device.proximityState;
    if ( newProximityState != oldProximityState ) {
        oldProximityState = newProximityState;
        [self setFaceDownOnSurface:newProximityState];
    }
}
float oldBrightness;
- (void)setFaceDownOnSurface:(BOOL)isFaceDownOnSurface
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        oldBrightness = [UIScreen mainScreen].brightness;
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(brightnessChanged:) name:UIScreenBrightnessDidChangeNotification object:[UIScreen mainScreen]];
    });
    float newBrightness = 0;
    if ( isFaceDownOnSurface ) {
        oldBrightness = [UIScreen mainScreen].brightness;
    } else {
        newBrightness = oldBrightness;
    }
    [UIApplication sharedApplication].idleTimerDisabled = isFaceDownOnSurface;
    [UIScreen mainScreen].wantsSoftwareDimming = isFaceDownOnSurface;
    [UIScreen mainScreen].brightness = newBrightness;
}
- (void)brightnessChanged:(NSNotification *)note
{
    oldBrightness = [UIScreen mainScreen].brightness;
}

Answer 2

使用加速度计来确定手机是否面朝下以激活接近审查程序效果良好。使用快速刷新率来确定手机何时翻转是至关重要的，就像你在已经被遮挡的情况下激活了接近检测仪一样，屏幕将保持打开状态。一旦手机关机，你可以降低刷新率以节省电池。