我的应用在iOS 7上运行良好,但在iOS 8 SDK上却无法运行。

CLLocationManager不返回位置,我没有看到我的应用程序下设置->位置服务。我在这个问题上做了谷歌搜索,但没有任何结果。会有什么问题呢?


当前回答

用于询问位置的旧代码将无法在iOS 8中使用。您可以尝试使用此方法进行位置授权:

- (void)requestAlwaysAuthorization
{
    CLAuthorizationStatus status = [CLLocationManager authorizationStatus];

    // If the status is denied or only granted for when in use, display an alert
    if (status == kCLAuthorizationStatusAuthorizedWhenInUse || status ==        kCLAuthorizationStatusDenied) {
        NSString *title;
        title = (status == kCLAuthorizationStatusDenied) ? @"Location services are off" :   @"Background location is not enabled";
        NSString *message = @"To use background location you must turn on 'Always' in the Location Services Settings";

        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title
                                                            message:message
                                                           delegate:self
                                                  cancelButtonTitle:@"Cancel"
                                                  otherButtonTitles:@"Settings", nil];
        [alertView show];
    }
    // The user has not enabled any location services. Request background authorization.
    else if (status == kCLAuthorizationStatusNotDetermined) {
        [self.locationManager requestAlwaysAuthorization];
    }
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if (buttonIndex == 1) {
        // Send the user to the Settings for this app
        NSURL *settingsURL = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
        [[UIApplication sharedApplication] openURL:settingsURL];
    }
}

其他回答

解决方案与向后兼容,不产生Xcode警告:

SEL requestSelector = NSSelectorFromString(@"requestWhenInUseAuthorization");
if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined &&
  [self.locationManager respondsToSelector:requestSelector]) {
((void (*)(id, SEL))[self.locationManager methodForSelector:requestSelector])(self.locationManager, requestSelector);
  [self.locationManager startUpdatingLocation];
} else {
  [self.locationManager startUpdatingLocation];
}

在Info.plist中设置NSLocationWhenInUseUsageDescription键。

对于iOS版本11.0+: 在Info.plist中设置NSLocationAlwaysAndWhenInUseUsageDescription键。还有另外2把钥匙。

我当时在开发一款升级到iOS 8的应用,位置服务停止了。你可能会在Debug区域得到一个错误,如下所示:

试图启动MapKit位置更新而没有提示位置授权。必须先调用-[CLLocationManager requestWhenInUseAuthorization]或-[CLLocationManager requestAlwaysAuthorization]。

我做了侵入性最小的手术。首先添加NSLocationAlwaysUsageDescription条目到你的info.plist:

注意,我没有填写这个键的值。这仍然有效,我并不担心,因为这是一个内部应用程序。此外,已经有一个标题要求使用位置服务,所以我不想做任何多余的事情。

接下来我为iOS 8创建了一个条件:

if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
    [_locationManager requestAlwaysAuthorization];
}

之后locationManager:didChangeAuthorizationStatus:方法为call:

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:  (CLAuthorizationStatus)status
{
    [self gotoCurrenLocation];
}

现在一切正常。和往常一样,请查看文档。

为了确保这与iOS 7向后兼容,你应该检查用户运行的是iOS 8还是iOS 7。例如:

#define IS_OS_8_OR_LATER ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)

//In ViewDidLoad
if(IS_OS_8_OR_LATER) {
   [self.locationManager requestAlwaysAuthorization];
}

[self.locationManager startUpdatingLocation];

这是ios 8的问题 将此添加到代码中

if (IS_OS_8_OR_LATER)
{
    [locationmanager requestWhenInUseAuthorization];

    [locationmanager requestAlwaysAuthorization];
}

到info.plist:

 <key>NSLocationUsageDescription</key>
 <string>I need location</string>
 <key>NSLocationAlwaysUsageDescription</key>
 <string>I need location</string>
 <key>NSLocationWhenInUseUsageDescription</key>
 <string>I need location</string>

我最终解决了自己的问题。

显然,在iOS 8 SDK中,在开始位置更新之前需要调用CLLocationManager上的requestAlwaysAuthorization(用于后台位置)或requestWhenInUseAuthorization(仅用于前台位置)。

在Info中还需要NSLocationAlwaysUsageDescription或NSLocationWhenInUseUsageDescription键。Plist并在提示符中显示一条消息。加上这些就解决了我的问题。

更多详细信息,请查看:Core-Location-Manager-Changes-in-ios-8