Question

我正在使用服务来跟踪用户的位置并在后台将数据发送到服务器来开发应用程序。这是基于GPS的应用程序。当我的程序使用GPS提供程序调用requestLocationUpdates时，永远不会调用onLocationChanged。但是，requestLocationUpdates可以在我的应用程序上与网络提供程序一起使用。请看一下我的代码。

Android版：4.1.2 装置：Galaxy nexus S

Tracker.java

private void init() {
    locationListener = new MyLocationListener();
    mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
    NOTIFICATION = R.string.local_service_started;
    arrivedStatus = false;
    activity = TrackerActivity.getAppActivity();
}

@Override
public void onCreate() {
    super.onCreate();
    init();
    Log.i(tag, "Start Tracking");
    showStartNotification();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i("LocalService", "Received start id " + startId + ": " + intent);
    tripID = intent.getExtras().getInt("tripID") + "";
    locationInterval = intent.getExtras().getInt("locationInterval")
            * MILLISECONDS_PER_SECOND;
    //lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
    //      locationInterval, 0, locationListener);
    getLocation();
    return START_STICKY;
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.e("STOP_SERVICE", "Service has stopped");
    mNM.cancel(R.string.local_service_started);
    lm.removeUpdates(locationListener);
    stopSelf();
}

private void getLocation() {
    lm = (LocationManager) getApplicationContext().getSystemService(
            Context.LOCATION_SERVICE);

    // getting GPS status
    isGPSEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);

    // getting network status
    isNetworkEnabled = lm
            .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

    if (!isGPSEnabled && !isNetworkEnabled) {
        // no network provider is enabled
        Log.e(tag, "Non providers are enabled");
    } else {

        if (isGPSEnabled) {
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                    locationInterval, 0, locationListener);
            Log.d(tag, "GPS Enabled");
        }

        if (isNetworkEnabled) {
            if (lm == null) {
                lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
                        locationInterval, 0, locationListener);
                Log.d(tag, "Network Enabled");
            }
        }
    }
}

@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

@SuppressWarnings("deprecation")
private void showStartNotification() {
    // In this sample, we'll use the same text for the ticker and the
    // expanded notification
    CharSequence text = getText(R.string.local_service_started);

    // Set the icon, scrolling text and timestamp
    Notification notification = new Notification(R.drawable.cameral, text,
            System.currentTimeMillis());

    // The PendingIntent to launch our activity if the user selects this
    // notification+
    PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
            new Intent(this, TrackerActivity.class), 0);

    // Set the info for the views that show in the notification panel.
    notification.setLatestEventInfo(this,
            getText(R.string.local_service_label), text, contentIntent);

    // Send the notification.
    mNM.notify(NOTIFICATION, notification);
}

/**
 * private void showStopSpecification() { CharSequence text =
 * getText(R.string.local_service_cancel); Notification notification = new
 * Notification(R.drawable.btn_save_dialog, text,
 * System.currentTimeMillis()); mNM.notify(NOTIFICATION, notification); }
 */

private void checkResult(JSONObject json) {
    try {
        if (json.getString(KEY_SUCCESS) != null) {
            String res = json.getString(KEY_SUCCESS);
            if (Integer.parseInt(res) == 1) {
                Log.v(tag, "Store data successfully");
                activity.findViewById(R.id.tracker_info)
                        .setBackgroundResource(R.color.blue4);
                if (json.getInt(ARRIVED_STATUS) == 1) {
                    setArrivedStatus(true);
                } else {
                    setArrivedStatus(false);
                }
            } else if (json.getString(KEY_ERROR).equals("1")) {
                // Error in login
                String error_msg = json.getString(KEY_ERROR_MSG);
                Log.e(tag, error_msg);
                setArrivedStatus(false);
            } else {
                Log.e(tag, "Something is wrong");
                setArrivedStatus(false);
            }
        } else {
            Log.e(tag, "Something is wrong");
            setArrivedStatus(false);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

public void setArrivedStatus(boolean status) {
    arrivedStatus = status;
}

public boolean getArrivedStatus() {
    return arrivedStatus;
}

private class MyLocationListener implements LocationListener {

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub
        currentLat = location.getLatitude() + "";
        currentLng = location.getLongitude() + "";
        Log.v(tag, LOCATION_CHANGED + " lat=" + currentLat + ", lon="
                + currentLng);
        try {
            JSONObject json = new LogInfo().execute(
                    new String[] { tripID, currentLat, currentLng }).get();
            checkResult(json);
            if (getArrivedStatus() == true) {
                Log.v(tag, "User has arrived safely");
                onDestroy();
            }
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ExecutionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

}

}

我也已经将权限添加到我的Manifest

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

谢谢

Answer 1

当您调用此功能时，您是否在设备的通知栏上看到GPS图标？如果是这样，这意味着它试图找到一个位置而你只是在一个没有GPS接收的地方。

在任何情况下，您都可以使用Google的方式来获取位置：https://developers.google.com/events/io/sessions/324498944

另外，什么是“追踪者”课程？这是一项服务吗？如果是这样，你不应该让它引用一个活动，因为它可能导致内存泄漏。而是使用正确的绑定。

你也应该避免调用“onDestroy”，因为调用它并不会真正关闭你的服务。而是调用“stopSelf”，并确保没有活动绑定它。

如果您愿意，我很久以前就问过这个问题（通过服务获取位置）here。

使用带有GPS提供程序的requestLocationUpdates永远不会调用onLocationChanged

1 个答案: