如何使用AsyncTask获取GPS位置？

I have seen many answers for this type of question but its not related with my task. I am trying to get gps location in background but i got exception as Cant Create Handler Inside Thread That Has Not Called Looper Prepare in Android in mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);.

我已经看到了很多这类问题的答案，但它与我的任务无关。我试图在背景中获得gps位置，但我得到例外，因为在线程中没有调用Looper的线程中创建处理程序在Android中的mlocManager.requestLocationUpdates（LocationManager.GPS_PROVIDER，0,0，mlocListener）;.

public class GPSLocation extends AsyncTask<Void, Void, Void>
    {  
        @Override
        protected void onPreExecute()
        {  
            super.onPreExecute(); 
            progressDialog = new ProgressDialog(RoadMaintenanceActivity.this);
            progressDialog.setCancelable(true);
            progressDialog.setMessage("Getting GPS Location...");
            progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            progressDialog.setProgress(1);
            progressDialog.show();

        } 
        @Override 
        protected void onProgressUpdate(Void... values) {
            super.onProgressUpdate(values);
            // Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
         }

        @Override 
        protected void onPostExecute(Void result)
        { 

                progressDialog.cancel(); 
        }
        @Override
        protected Void doInBackground(Void... params) { 

            boolean isGps = false;

            while(!isGps)
            { 
                LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
                LocationListener mlocListener = new MyLocationListener();  
                mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);   
                if(longitude !=0 && latitude!=0)
                {
                    isGps = true; 
                    sendSMS();
                }  
            } 

            return null;  


        }

     } 

I am not sure why we cant call that inside the doBackground() method.

我不知道为什么我们不能在doBackground（）方法中调用它。

Thanks for your help guys.

谢谢你的帮助。

3 个解决方案

#1

Finally i figured out the problem, I think this will help some one like me

最后我想出了问题，我认为这会对像我这样的人有所帮助

public class GPSLocation extends AsyncTask<Void, Void, Void>
    {  
        boolean running =true;
                @Override
                protected void onPreExecute()
                {  
                    super.onPreExecute(); 
                    progressDialog = new ProgressDialog(RoadMaintenanceActivity.this);
                    progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
                          public void onCancel(DialogInterface dialog) {
                              getgps.cancel(true);  
                          }
                    });
                    LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
                    LocationListener mlocListener = new MyLocationListener();  
                    mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);    
                    progressDialog.setCancelable(true);
                    progressDialog.setMessage("Getting GPS Location...");
                    progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                    progressDialog.setProgress(1);
                    progressDialog.show();

                } 

                @Override 
                protected void onProgressUpdate(Void... values) {
                    super.onProgressUpdate(values);
                    // Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
                 }

                @Override 
                protected void onPostExecute(Void result)
                {  
                        progressDialog.cancel(); 
                }

                @Override
                protected Void doInBackground(Void... params) {  
                    boolean isDataSubmitted = false;

                    while(!isDataSubmitted)
                    {  
                        if(longitude !=0 && latitude!=0)
                        { 
                            sendSMS();
                            isDataSubmitted = true;  
                        }  
                    } 

                    return null;    
                } 
     } 

By having Locationmanager in onPreExecute() the exception get rid out from my application. We can get the gps in onpreexecute rather than doinbackground().

通过在onPreExecute（）中使用Locationmanager，异常将从我的应用程序中删除。我们可以在onpreexecute而不是doinbackground（）中获取gps。

#2

You can't do that.The mlocListener requires a Looper thread to operate.

你不能这样做.mlocListener需要一个Looper线程才能运行。

in doInBackground Call Looper.prepare();

在doInBackground中调用Looper.prepare（）;

So your code will become something like this.

所以你的代码将变成这样的东西。

@Override
        protected Void doInBackground(Void... params) { 
            Looper.myLooper().prepare();
            boolean isGps = false;
            -----------------

#3

this seems suitable for what I'm trying to do at the moment. Any chance you can show me the full source? I currently have it worked into my code, but I'd like to see how you are getting the GPS co ords and starting the async

这似乎适合我现在正在尝试做的事情。你有机会向我展示完整的消息来源吗？我目前已将其用于我的代码，但我想看看你如何获得GPS协议并开始异步

ProgressDialog progressDialog;
double longitude, latitude;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_confirm_screen);
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
    Boolean locationCheck = sp.getBoolean("LOCATION", false);
   if(locationCheck){

    }
   else
   {
    sendEmail();
    playSound();
   }

}

public class GPSLocation extends AsyncTask<Void, Void, Void>
{  
    boolean running =true;
            @Override
            protected void onPreExecute()
            {  
                super.onPreExecute(); 
                progressDialog = new ProgressDialog(ConfirmScreen.this);
                progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
                      public void onCancel(DialogInterface dialog) {
                          getgps.cancel(true);  
                      }
                });

                LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
                LocationListener mlocListener = new MyLocationListener();  
                mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);    
                progressDialog.setCancelable(true);
                progressDialog.setMessage("Getting GPS Location...");
                progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                progressDialog.setProgress(1);
                progressDialog.show();

            } 

            @Override 
            protected void onProgressUpdate(Void... values) {
                super.onProgressUpdate(values);
                // Things to be done while execution of long running operation is in progress. For example updating ProgessDialog
             }

            @Override 
            protected void onPostExecute(Void result)
            {  
                    progressDialog.cancel(); 
            }

            @Override
            protected Void doInBackground(Void... params) {  
                boolean isDataSubmitted = false;

                while(!isDataSubmitted)
                {  
                    if(longitude !=0 && latitude!=0)
                    { 
                        sendEmail();
                        isDataSubmitted = true;  
                    }  
                } 

                return null;    
            } 
 } 


public void backHome(View view) 
{
    Intent intent = new Intent (this, MainScreen.class);
    startActivity(intent);
}

// Method to start playing and looping a sound.

public void playSound()
{
    MediaPlayer clickSound = MediaPlayer.create(this, R.raw.warning);
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
    Boolean soundCheck = sp.getBoolean("SOUND", false);
    if (soundCheck)
    {
        clickSound.start();
    }



}// method end

public void sendEmail()
{
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
    String nameValue = sp.getString("NAME", "failed to get name");
    String emailValue = sp.getString("EMAIL", "failed to get email");
    Intent i = new Intent(Intent.ACTION_SEND);
    i.setType("message/rfc822");
    i.putExtra(Intent.EXTRA_EMAIL, new String[]{emailValue});
    i.putExtra(Intent.EXTRA_SUBJECT, "Email sent from DON'T PANIC - A Chris O'Brien Project");
    i.putExtra(Intent.EXTRA_TEXT, "Hi there\n" + nameValue + " is in mortal danger. They didn't include co-ords as they assume you know where they are..\nKind Regards\nDon't Panic! \n\n\n");

    try
    {   startActivity(Intent.createChooser(i, "Send mail...."));
    } 
    catch (android.content.ActivityNotFoundException ex){

        Toast.makeText(ConfirmScreen.this, "There are no email clients installed or set up", Toast.LENGTH_SHORT).show();
    }
}


public void sendEmail(String a, String b, String c)
{
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
    String nameValue = sp.getString("NAME", "failed to get name");
    String emailValue = sp.getString("EMAIL", "failed to get email");
    Intent i = new Intent(Intent.ACTION_SEND);
    i.setType("message/rfc822");
    i.putExtra(Intent.EXTRA_EMAIL, new String[]{emailValue});
    i.putExtra(Intent.EXTRA_SUBJECT, "Email sent from DON'T PANIC - A Chris O'Brien Project");
    i.putExtra(Intent.EXTRA_TEXT, "Hi there\n" + nameValue + " is in mortal danger. Please see the co-ords attached and run to their rescue!" +
            " If you don't see any co-ords, they didn't check the box and assume you know where they are.\nKind Regards\nDon't Panic! \n\n\n" + 
            a + b + c);

    try
    {   startActivity(Intent.createChooser(i, "Send mail...."));
    } 
    catch (android.content.ActivityNotFoundException ex){

        Toast.makeText(ConfirmScreen.this, "There are no email clients installed or set up", Toast.LENGTH_SHORT).show();
    }
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_confirm_screen, menu);
    return true;
}






}