如何在后台运行locationlistener

本文介绍了如何在后台运行locationlistener的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我想在我的应用程序上运行一个位置监听器，该监听器每隔10m或每5秒发送一次新的弹出式窗口".稍后，我会将数据发送到云中.

I would like to run a locationlistener on my app, that send after every 10m or every 5 seconds an new "Popup". Later I will send my data to the cloud.

这是我的GPSTracker课:

This is my GPSTracker class:

import android.app.AlertDialog; import android.app.Service; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.os.IBinder; import android.provider.Settings; import android.util.Log; import android.widget.Toast; public class GPSTracker extends Service implements LocationListener { private final Context mContext; // flag for GPS status boolean isGPSEnabled = false; // flag for network status boolean isNetworkEnabled = false; // flag for GPS status boolean canGetLocation = false; Location location; // location double latitude; // latitude double longitude; // longitude // The minimum distance to change Updates in meters private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters // The minimum time between updates in milliseconds private static final long MIN_TIME_BW_UPDATES = 1000 * 5 * 1; // 1 minute // Declaring a Location Manager protected LocationManager locationManager; public GPSTracker(Context context) { this.mContext = context; getLocation(); } public Location getLocation() { try { locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE); // getting GPS status isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER); // getting network status isNetworkEnabled = locationManager .isProviderEnabled(LocationManager.NETWORK_PROVIDER); if (!isGPSEnabled && !isNetworkEnabled) { // no network provider is enabled } else { this.canGetLocation = true; if (isNetworkEnabled) { locationManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); Log.d("Network", "Network"); if (locationManager != null) { location = locationManager .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); if (location != null) { latitude = location.getLatitude(); longitude = location.getLongitude(); } } } // if GPS Enabled get lat/long using GPS Services if (isGPSEnabled) { if (location == null) { locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); Log.d("GPS Enabled", "GPS Enabled"); if (locationManager != null) { location = locationManager .getLastKnownLocation(LocationManager.GPS_PROVIDER); if (location != null) { latitude = location.getLatitude(); longitude = location.getLongitude(); } } } } } } catch (Exception e) { e.printStackTrace(); } return location; } /** * Stop using GPS listener * Calling this function will stop using GPS in your app * */ public void stopUsingGPS(){ if(locationManager != null){ locationManager.removeUpdates(GPSTracker.this); } } /** * Function to get latitude * */ public double getLatitude(){ if(location != null){ latitude = location.getLatitude(); } // return latitude return latitude; } /** * Function to get longitude * */ public double getLongitude(){ if(location != null){ longitude = location.getLongitude(); } // return longitude return longitude; } /** * Function to check GPS/wifi enabled * @return boolean * */ public boolean canGetLocation() { return this.canGetLocation; } /** * Function to show settings alert dialog * On pressing Settings button will lauch Settings Options * */ public void showSettingsAlert(){ AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext); // Setting Dialog Title alertDialog.setTitle("GPS is settings"); // Setting Dialog Message alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?"); // On pressing Settings button alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog,int which) { Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); mContext.startActivity(intent); } }); // on pressing cancel button alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { dialog.cancel(); } }); // Showing Alert Message alertDialog.show(); } @Override public void onLocationChanged(Location location) { } @Override public void onProviderDisabled(String provider) { } @Override public void onProviderEnabled(String provider) { Toast.makeText(GPSTracker.this,"Provider enabled by the user. GPS turned on",Toast.LENGTH_LONG).show(); } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } @Override public IBinder onBind(Intent arg0) { return null; } }

对于我的活动课，我做到了:

For my activityclass I have made this:

gps = new GPSTracker(MainActivity.this); double latitude2 = gps.getLatitude(); double longitude2 = gps.getLongitude();

我收到了数据，这行得通.但是现在我想在后台运行数据，因此当位置更改时，我可以实现一个将数据发送到云的功能.

I receive the data, this works. But now I want to run the data in the background so when the location is changed I can implement a function that sends my data to the cloud.

我尝试过:

private void startGPSTrackerInBackground() { new AsyncTask<Void,Void,String>() { @Override protected String doInBackground(Void... params) { String msg = "This message runs in background"; gps = new GPSTracker(MainActivity.this); if(!gps.canGetLocation()){ gps.showSettingsAlert(); }else{ gps = new GPSTracker(MainActivity.this); double latitude2 = gps.getLatitude(); double longitude2 = gps.getLongitude(); } return msg; } @Override protected void onPostExecute(String msg) { mDisplay.append(msg + "\n"); } }.execute(null, null, null); }

但是在此功能中，无法获取我的GPSTracker类的信息，有人想办法做到这一点吗?

But in this function it's not possible to get the information of my GPSTracker class, anyone an idea to make this possible?

推荐答案

创建一个独立的类，添加一个GPSTracker成员变量并将其传递到构造函数中.将任务包装在可以稍后调用的方法中:

Create an independent class, add a GPSTracker member variable and pass it in the constructor. Wrap your task in a method you can invoke later:

public class BackgroundGPSTracker() { GPSTracker tracker; public BackgroundGPSTracker(GPSTracker tracker) { this.tracker = tracker; } public void run() { new AsyncTask<Void,Void,String>() { @Override protected String doInBackground(Void... params) { // Do some background stuff. } @Override protected void onPostExecute(String msg) { // Do after work stuff } }.execute(null, null, null); } }

使用:

如果您这样创建GPSTracker:

If you create GPSTracker like this:

gps = new GPSTracker(MainActivity.this);

然后您启动将其传递给任务的活动:

Then you start the activity passing it to the task:

BackgroundGPSTracker bgGPSTracker= new BackgroundGPSTracker(gps); bgGPSTracker.run();

编辑

EDIT

使用成员变量存储最近的已知位置，并使用计时器安排更新时间:

Use a member variable to store last known location, and timer to schedule updates:

public class CampaignsDiscoverActivity extends Activity{ static final int QUERY_CAMPAINGS_DELAY = 30000;// milliseconds Location currentLocation; Timer timer; void restartTimer() { timer = new Timer(); timer.schedule(new TimerTask() { @Override public void run() { sendDataToServerOrWhatever(); } }, QUERY_CAMPAINGS_DELAY, QUERY_CAMPAINGS_DELAY); } void stopTimer() { if (timer != null) { timer.cancel(); timer = null; } } void sendDataToServerOrWhatever() { // Do some stuff using currentLocation }

设置位置更改的侦听器.引发位置更改后，请停止计时器，开始工作并重新启动它:

Set a listener for locations changes. when location changed is raised, stop the timer, do work and restart it:

void startGPSUpdates() { locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); locationListener = new LocationListener() { @Override public void onStatusChanged(String provider, int status, Bundle extras) { } @Override public void onProviderEnabled(String provider) { } @Override public void onProviderDisabled(String provider) { } @Override public void onLocationChanged(Location location) { stopTimer(); currentLocation = location; sendDataToServerOrWhatever(); } }; locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener); // Initialize location. currentLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); if (currentLocation == null) { currentLocation = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); } restartTimer(); }

要启动系统，只需调用startGPSUpdates.

To start the system just invoke startGPSUpdates.

当应用程序进入后台时，您应暂停监听器，并在前台进入时恢复:

You should pause listeners when app goes to the background and resume when foreground:

@Override public void onPause() { super.onPause(); if (applicationData.isLoggedIn()) { pauseLocationUpdates(); } } @Override public void onResume() { super.onResume(); if (applicationData.isLoggedIn()) { resumeLocationUpdates(); } } void pauseLocationUpdates() { locationManager.removeUpdates(locationListener); } void resumeLocationUpdates() { locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener); }

我认为您应该对计时器执行相同的操作，但是我使用该计时器的应用尚未完成并经过全面测试，因此您可能会发现错误.

I think you should do the same with the timer, but the app where I'm using it is not finished and fully tested yet, so you might find bugs.

希望有帮助.