shows user location 在 iOS 8 上失效

在 iOS 7 以及更早之前的版本,MapView 顯示使用者位置不需實作到 CLLocationManager ,現在都要了。

在 iOS 8 上編譯會出現以下 log :

Trying to start MapKit location updates without prompting for location authorization. Must call -[CLLocationManager requestWhenInUseAuthorization] or -[CLLocationManager requestAlwaysAuthorization] first.

 

首先必須要修改 info.plist
新增 key值為 NSLocationWhenInUseUsageDescription 或 NSLocationAlwaysUsageDescription
Value值為要出現在螢幕上的字,終於可以客製化訊息了!但也可以留白。
兩者差異僅在前者只有使用中才會定位,後者是在背景也會持續定位。

 

接著修改程式碼,第5行是重點


locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy=kCLLocationAccuracyBest;
if([locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
[locationManager requestWhenInUseAuthorization];
}
[locationManager startUpdatingLocation];

 

另外授權檢查部分也要修改,請注意4,5行的差異


- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {

if (
([locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)] && status != kCLAuthorizationStatusNotDetermined && status != kCLAuthorizationStatusAuthorizedWhenInUse) ||
(![locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)] && status != kCLAuthorizationStatusNotDetermined && status != kCLAuthorizationStatusAuthorized)
) {

NSString *message = @"您的手機目前並未開啟定位服務,如欲開啟定位服務,請至設定->隱私->定位服務,開啟本程式的定位服務功能";
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"無法定位" message:message delegate:nil cancelButtonTitle:@"確定" otherButtonTitles: nil];
[alertView show];

}else {

[locationManager startUpdatingLocation];
}
}

上面那行是 iOS 8 以上,第二行是 iOS 7 以下,因為 kCLAuthorizationStatusAuthorized 在 iOS 8 完全不能使用。

 

別的地方要這樣寫


CLAuthorizationStatus status = [CLLocationManager authorizationStatus];
    
    if (status == kCLAuthorizationStatusAuthorizedWhenInUse || status == kCLAuthorizationStatusAuthorized) {

// 開始定位

}else {

// 顯示警告
}

發表迴響