Question

我想在我的应用程序中获取当前位置（纬度和经度值）。我使用了以下代码。

问题是-----------------＆gt;

 When the Best provider is GPS,Location returned  is null.

我学到了一些SO帖子，我将LocationListener添加到我的代码中，然后它工作了但是当我重新启动设备并再次运行应用程序时，它在Provider为GPS时提供相同的NULL值。我不明白为什么它现在不起作用。

我还了解到Gps提供程序获取值的速度很慢，因此我必须添加LocationListener来解决此问题。所以，我将此添加到我的代码中

  LocationListener locationListener = new MyLocationListener();
            locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 35000, 10, locationListener);

此处完整代码-----------＆gt;

      public void getCurrentlocation()
    {
        String providers = Settings.Secure.getString(getContentResolver(), Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
        Log.e("provider"," "+providers);
        if(!providers.contains("gps")){
          final Intent poke = new Intent();
          poke.setClassName("com.android.settings", "com.android.settings.widget.SettingsAppWidgetProvider");
          poke.addCategory(Intent.CATEGORY_ALTERNATIVE);
          poke.setData(Uri.parse("3")); 
          sendBroadcast(poke);
          Log.e("your gps is","enabled");
        }
        LocationListener locationListener = new MyLocationListener();
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 35000, 10, locationListener);
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 35000, 10, locationListener);
           // Define the criteria how to select the locatioin provider -> use
           // default
           Criteria criteria = new Criteria();
           String provider = locationManager.getBestProvider(criteria,true);
           Log.e("location provider",""+provider);
           Location location = locationManager.getLastKnownLocation(provider);

           // Initialize the location fields
           if (location != null) 
           {
            System.out.println("Provider " + provider + " has been selected.");
            strLatitude=String.valueOf(location.getLatitude());
                  strLongitude=String.valueOf(location.getLongitude());
                  Log.e("lattitude",strLatitude);
                  Log.e("logntitude",strLongitude);
                  latituteField.setText( strLatitude);
                  longitudeField.setText(strLongitude);
           }
           else 
           {


                  strLatitude=String.valueOf(0);
                  strLongitude=String.valueOf(0);
                  Log.e("lattitude",strLatitude);
                  Log.e("logntitude",strLongitude);
                  latituteField.setText( strLatitude);
                  longitudeField.setText(strLongitude);
           }




     } 



    private class MyLocationListener implements LocationListener
    {

        @Override
        public void onLocationChanged(Location location)
        {

//            mLattitude = location.getLatitude();
//            mLongitude = location.getLongitude();
//
//            Log.w("value : ",
//                    String.valueOf(location.getLatitude()) + String.valueOf(location.getLongitude())
//                            + 
//
//
//            context.sendBroadcast(new Intent(Constants.BRDCAST_LOCATION_UPDATED));

        }

        @Override
        public void onProviderDisabled(String provider)
        {
            // Log.w("provider", provider);

        }

        @Override
        public void onProviderEnabled(String provider)
        {
            // Log.w("provider", provider);

        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras)
        {
            // Log.w("status", String.valueOf(status));

        }


}

请帮助

提前致谢

Answer 1

好吧，我尝试了下面的代码，它取得了纬度和经度：

公共类MainActivity扩展了Activity {

@Override
public void onCreate(Bundle savedInstanceState)
{
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

/* Use the LocationManager class to obtain GPS locations */

  LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);  
  List<String> providers = lm.getProviders(true);

/ *向后循环数组，如果你得到一个准确的位置，那么就打破循环* /

      Location location = null;

      for (int i=providers.size()-1; i>=0; i--) {
              location = lm.getLastKnownLocation(providers.get(i));
              if (location != null) break;
      }

      String Text = "My current location is: " +
              "Latitud = " + location.getLatitude() +
              "Longitud = " + location.getLongitude();

              Toast.makeText( getApplicationContext(), Text, Toast.LENGTH_SHORT).show();
   }

的AndroidManifest.xml：

请参阅设置以下权限：

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

Gps提供程序返回Null位置

1 个答案: