Question

我的Android服务有问题。在“onLocationChanged”中，我想访问我的类“Device”的静态成员。

我用以下方式开始服务：

Intent i = new Intent(this, LocationService.class);
   startService(i);

这是我的类LocationListener，其中包含服务：

private class LocationListener implements android.location.LocationListener{
    Location mLastLocation;
    LocationListener(String provider)
    {
        Log.e(TAG, "LocationListener " + provider);
        mLastLocation = new Location(provider);
    }
    @Override
    public void onLocationChanged(Location location)
    {
         Device.getLocationType().setLocationData(location);
    }

    @Override
    public void onProviderDisabled(String provider)
    {
      //...
    }

    @Override
    public void onProviderEnabled(String provider)
    {
       //...
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras)
    {
        //...
    }
}


LocationListener[] mLocationListeners = new LocationListener[] {
        new LocationListener(LocationManager.GPS_PROVIDER),
        new LocationListener(LocationManager.NETWORK_PROVIDER)
};


@Override
public IBinder onBind(Intent arg0)
{
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
    super.onStartCommand(intent, flags, startId);
    Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
    Log.d(TAG, "onStartCommand");
    return START_STICKY;
}

@Override
public void onCreate()
{
    super.onCreate();
    Log.d(TAG, "onCreate");
    initializeLocationManager();
    try {
        mLocationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DISTANCE,
                mLocationListeners[1]);
        Log.d(TAG, "try");
    } catch (java.lang.SecurityException ex) {
        Log.d(TAG, "fail to request location update, ignore", ex);
    } catch (IllegalArgumentException ex) {
        Log.d(TAG, "network provider does not exist, " + ex.getMessage());
    }
    try {
        mLocationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, MIN_TIME, MIN_DISTANCE,
                mLocationListeners[0]);
        Log.d(TAG, "try2");
    } catch (java.lang.SecurityException ex) {
        Log.d(TAG, "fail to request location update, ignore", ex);
    } catch (IllegalArgumentException ex) {
        Log.d(TAG, "gps provider does not exist " + ex.getMessage());
    }
}

@Override
public void onDestroy()
{
    Log.e(TAG, "onDestroy");
    super.onDestroy();
    if (mLocationManager != null) {
        for (int i = 0; i < mLocationListeners.length; i++) {
            try {
                mLocationManager.removeUpdates(mLocationListeners[i]);
            } catch (Exception ex) {
                Log.i(TAG, "fail to remove location listners, ignore", ex);
            }
        }
    }
}


private void initializeLocationManager() {
    Log.e(TAG, "initializeLocationManager");
    if (mLocationManager == null) {
        mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
    }
}

我的班级设备

public class Device {
private static LocationType locationType;

//...
}

类LocationType

public class LocationType {
private Location location;

public LocationType(){

    //...
}

Location getLocationData() {
    return location;
}

void setLocationData(Location location) {
    this.location = location;
}
}

我的申请失败了，因为我无权从服务中访问静态成员？我如何访问这个静态成员？

非常感谢您的回答。

Answer 1

你的字段是私人的

private static LocationType locationType;

公开并且应该可以访问

public static LocationType locationType;

如果不是这样，你至少应该制作一个静态的getter，它是public或package private。如果它的包是私有的，请确保这两个类都在同一个包中。

Answer 2

你使用Device.getLocationType()你确定这个方法也是静态的吗？因此，要么将其设为静态，要么公开locationType并直接访问它。

你是否想要完全是另一回事。

另外，请尝试替换：

private static LocationType locationType;

with：

private static LocationType locationType = new LocationType();

Answer 3

我的对象＆＃34; locationType＆＃34;始终定义为null ...在我的MainActivity中，我调用方法Device.init（...）。此方法在静态成员中创建对象LocationType。

public class Device {
private static LocationType locationType;

 public static void init(...){
    Device.locationType = new LocationType(...);

    if(Device.locationType != null){
        Intent i = new Intent(activity, LocationService.class);
        activity.startService(i);
    }
}

我的服务已启动，但在服务方法＆＃34; onLocationChanged＆＃34;中，Device.locationType为null。

Android Service访问另一个类的静态成员

3 个答案: