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标题: ios - CLLocationManager 委托(delegate)方法未在后台调用 [打印本页]

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作者: 菜鸟教程小白    时间: 2022-12-13 14:03
标题: ios - CLLocationManager 委托(delegate)方法未在后台调用

我正在构建一个应用程序来检查用户是否在我客户的商店附近，如果是，它会向他发送通知。

我也希望应用在后台检查它。

我已将此行添加到我的 info.plist 文件中:

image

这是我的代码:

AppDelegate.m:

-(BOOL)applicationUIApplication *)application willFinishLaunchingWithOptionsNSDictionary *)launchOptions
{
[self configureLocationManager];
[self.locationManager startUpdatingLocation];

return YES;
}
-(void)configureLocationManager
{
    //Initializing locationManager
    self.locationManager=[[CLLocationManager alloc] init];
    //setting "locationManager"'s(CLLocationManager) delegate to "self"
    self.locationManager.delegate=self.monitorLocationVC;
    //Setting "locationManager"'s(CLLocationManager)'s distance filter to none
    //self.locationManager.distanceFilter=kCLDistanceFilterNone;
    //Setting "locationManager"'s(CLLocationManager)'s activityType to navigation
    self.locationManager.activityType=CLActivityTypeAutomotiveNavigation;
    //setting "locationManager"'s(CLLocationManager) desiredAccuracy to "best"
    self.locationManager.desiredAccuracy=kCLLocationAccuracyBestForNavigation;
    //If OS version is 9 or above - setting "allowsBackgroundLocationUpdates" to YES
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 9) {
        self.locationManager.allowsBackgroundLocationUpdates = YES;
    }
}

MonitorLocationViewController.m:

-(void)locationManagerCLLocationManager *)manager didUpdateLocationsNSArray<CLLocation *> *)locations
{
    [self checkIfNearStore]; //Not being called in background
}

-(void)checkIfNearStore
{
    for (Store *currentStore in self.allStores) {
        if ([currentStore.circularRegion containsCoordinate:self.locationManager.location.coordinate]&&currentStore.alreadySendNotification==NO) {
            NSLog(@"Entered: %@",[[self storeForRegion:currentStore.circularRegion] address]);
            currentStore.alreadySendNotification=YES;
            [self.storesAlreadySentNotifications addObject:currentStore];
        }
    }

    for (Store *currentStore in self.storesAlreadySentNotifications) {
        if (![currentStore.circularRegion containsCoordinate:self.locationManager.location.coordinate]) {
            currentStore.alreadySendNotification=NO;
        }
    }
}

有人有想法吗？谢谢!

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Best Answer-推荐答案

后台位置更新

我建议您仔细阅读与 startMonitoringSignificantLocationChanges 相关的讨论。方法(您必须使用此方法来解决问题)。请注意，您可以通过调用 stopMonitoringSignificantLocationChanges 然后再次调用 start... 方法来强制进行新更新。您还需要在 locationManager:didUpdateLocations 方法中监控时间戳。

Apple 详细说明了当应用处于后台时获取更新所需的步骤。基本上你必须在你的应用委托(delegate)方法中截取一个键。这个SO question有示例代码。

但是在您跳到代码之前，请按照建议查看讨论，因为它会让您更清楚地了解如何掌握这种行为。与往常一样，您也总是希望监控讨论中提到的失败委托(delegate)方法。

苹果Documentation

Nota Bene

Apple 已发布此非常重要的说明，说明位置更新发送到设备的频率限制。为了节省电池，他们尝试限制更新次数，直到设备移动 500 米。您的测试应考虑这些限制。

资源

有关更多补充信息，请注意以下对这些 SO 问题的回答:

#1 #2

关于ios - CLLocationManager 委托(delegate)方法未在后台调用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35171872/

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