Android:如何在后台永远运行应用程序？

Question

我创建了一个将用户位置发送到服务器的应用程序..它使用异步任务(doInBackground 和 onPostExecute 方法)在后台运行...但它运行速度很慢..在编码中我使用了 Thread.sleep(300000 ) 间隔 5 分钟...我认为应用程序停止运行..

YasarKhan.java

    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 = 1000; // 1000
                                                                        // meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 20; // 20 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;
    boolean done = true;

//  public YasarKhan(Context context) {
//      this.mContext = context;
//      
//
//  }



    public void gpsTraking() {

        // check if GPS enabled
        if (true) {
            stAdd = "";
            double latitude = getLatitude();
            double longitude = getLongitude();
            Geocoder gc = new Geocoder(getBaseContext());
            try
            {
                List<Address> list = gc.getFromLocation(latitude, longitude, 2);
                Address a = list.get(0);
                for (int i = 0; i <= a.getMaxAddressLineIndex(); i++) {
                    stAdd = stAdd + "\n " + a.getAddressLine(i);
                }
                stAdd = stAdd + " " + a.getLocality() + "\n"
                        + a.getFeatureName();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


    }

    public void passing() 
    {
        new SendFeedback().execute(imei,simSerialNumber,stAdd,currentTime);
    }


    class SendFeedback extends AsyncTask<String, Void, String> 
    {
        @Override
        protected String doInBackground(String... paramArrayOfParams) 
        {
            SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
            request.addProperty("strIMEINumber", paramArrayOfParams[0]);
            request.addProperty("strSIMNumber", paramArrayOfParams[1]);     
            request.addProperty("strAddress", paramArrayOfParams[2]);
            request.addProperty("strTime", paramArrayOfParams[3]);

            SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
            envelope.dotNet = true;
            envelope.encodingStyle = SoapSerializationEnvelope.ENC;
            envelope.setOutputSoapObject(request);
            System.setProperty("http.keepAlive", "false");

            try 
            {
                HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
                androidHttpTransport.call(SOAP_ACTION, envelope);
                // SoapObject result = (SoapObject) envelope.getResponse();
                SoapPrimitive response = (SoapPrimitive) envelope.getResponse();
                String resultData = response.toString();
                Log.d("response", resultData);
                return resultData;              
            } 
            catch (Exception e) 
            {
                Log.d("My Error", "" + e.getMessage());

            }
            return resultData;
        }

        @Override
        protected void onPostExecute(String result) 
        {
            Log.d("strResult", result);
            super.onPostExecute(result);
        }
    }
}

MyReceiver.java

package com.example.yasar;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class MyReceiver extends BroadcastReceiver {


         public static final String TAG = "com.example.gpstraking";
         @Override
         public void onReceive(Context context, Intent intent) 
         {

             try
             { 

                 Intent serviceIntent = new Intent(context, YasarKhan.class);
                context.startService(serviceIntent);     
             }
             catch(Exception e)
             {
                 Log.e("My Service Error",e.getMessage());
             }


        }



}

主 Activity .java

package com.example.yasar;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d("naveeeen","kushwaaahaACTIVITY");
        Intent serviceIntent = new Intent(this, YasarKhan.class);
        this.startService(serviceIntent);

    }



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        //getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

Answer 1

在 onStartCommand() 中使用服务:

1. 使用 requestLocationUpdates。

   locationManager.requestLocationUpdates(provider, 5000, 0, myLocationListener);
   

2. 在onStartCommand()中调用此方法检查提供者

    public void testProviders() 
       { 
           //Choose only one provider                    
           Location location = locationManager.getLastKnownLocation(provider);      
           if (location != null)
           {
               lat = location.getLatitude();
               lng = location.getLongitude();
               str = "Test Provider method says :"+" Latitude = " +lat + " and " + " Longitude = " +lng;
               System.err.println("Current Latitude and Longitude:"+lat+","+lng);
   
           }                
           else
           {
               str = " No Location ";
           }
           System.err.println(str);
           Toast.makeText(getApplicationContext(), str, Toast.LENGTH_SHORT).show();
       }
   

3. 使用监听器

    LocationListener myLocationListener = new LocationListener()
       {
   
           @Override
           public void onLocationChanged(Location location) 
           {
               if (location != null)
               {
                   Clat = location.getLatitude();
                   Clng = location.getLongitude();          
                   System.out.println("Change latitude and Longitude:"+Clat+", "+Clng+"timer: " +System.currentTimeMillis());                        
                   String str = " LocationListener : Change latitude and Longitude: " +Clat+ ", " +Clng+ "  timer: "  +System.currentTimeMillis();
                   System.err.println(str);
                   Toast.makeText(getApplicationContext(), str, Toast.LENGTH_SHORT).show();
                   new SendPGLocationToServer().execute();
               }
               else
               {
                   str = " No Location. ";
                   Toast.makeText(getApplicationContext(), str, Toast.LENGTH_SHORT).show();
               }
           }
   

4. 最后，使用 AsyncTask 将位置发送到服务器。