ios 里如何判断当前应用的定位服务是否可用

如何在某个程序里面判定当前应用程序的定位服务是否可用

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2013 年的答案太老了， iOS 4.2 以后可以用 +(BOOL)locationServicesEnabled 和 + (CLAuthorizationStatus)authorizationStatus 两个方法来检查，前者是检查手机是否开启了定位，后者是检查应用是否拥有定位的权限。

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SO上有一个答案。

[CLLocationManager locationServicesEnabled]检测的是整个iOS系统的位置服务开关，无法检测当前应用是否被关闭，只能通过CLLocationManagerDelegate的locationManager:didFailWithError:方法去检测：

- (void)locationManager: (CLLocationManager *)manager
       didFailWithError: (NSError *)error {

    NSString *errorString;
    [manager stopUpdatingLocation];
    NSLog(@"Error: %@",[error localizedDescription]);
    switch([error code]) {
        case kCLErrorDenied:
            //Access denied by user
            errorString = @"Access to Location Services denied by user";
            //Do something...
            break;
        case kCLErrorLocationUnknown:
            //Probably temporary...
            errorString = @"Location data unavailable";
            //Do something else...
            break;
        default:
            errorString = @"An unknown error has occurred";
            break;
        }
    }

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:errorString delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
    [alert show];
    [alert release];
}

具体的CLError信息可以看CLLocationManager文档