在Android上的位置應用程序

Question

我有穩定閱讀的問題，從這個應用程序開始。 在第一分鐘左右閱讀變得非常激動。即使在距離上也有10-100米之差。 我聽說它是​​位置應用程序中的常見錯誤，尤其是使用GPS的應用程序。 我可以通過暫停閱讀這個開始以某種方式防止這種情況嗎？用一些像「計算你的位置」或類似的東西在第一個10-20秒這樣的花哨文本？
如果是。我應該在哪裏實施這個暫停？所以它會得到讀數並穩定它們，但不要搞亂計算？ 或者還有其他方法可以防止凌亂的閱讀？ OFC上也是最新的升級非常歡迎:)

import java.io.IOException; 
import java.util.List; 
import java.util.Locale; 
import android.app.Activity; 
import android.content.Context; 
import android.location.Address; 
import android.location.Criteria; 
import android.location.Geocoder; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.widget.TextView; 
public class MainActivity extends Activity { 

    String addressString = "No address found"; 
    String latLongString = "Your Current Position is: "; 

    double latitude = 10; 
    double longitude = 10; 
    double sLatitude; 
    double sLongitude; 
    double eLatitude; 
    double eLongitude; 
    double distance = 10; 
    double el1 = 0; 
    double el2 = 0; 
    double counter = 2; 

    TextView myLocationText; 
    TextView myLatitude; 
    TextView myLongitude; 
    TextView myAddress; 
    TextView startingLatitude; 
    TextView startingLongitude; 
    TextView endingLatitude; 
    TextView endingLongitude; 
    TextView myDistance; 
    TextView myLogOut; 

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

     LocationManager locationManager; 
     String context = Context.LOCATION_SERVICE; 
     locationManager = (LocationManager) getSystemService(context); 

     Criteria criteria = new Criteria(); 
     criteria.setAccuracy(Criteria.ACCURACY_FINE); 
     criteria.setAltitudeRequired(false); 
     criteria.setBearingRequired(false); 
     criteria.setCostAllowed(true); 
     criteria.setPowerRequirement(Criteria.POWER_LOW); 

     String provider = locationManager.getBestProvider(criteria, true); 
     Location location = locationManager.getLastKnownLocation(provider); 

     myLatitude = (TextView) findViewById(R.id.Latitude); 
     myLongitude = (TextView) findViewById(R.id.Longitude); 
     myLocationText = (TextView) findViewById(R.id.myLocationText); 
     myAddress = (TextView) findViewById(R.id.Address); 
     startingLatitude = (TextView) findViewById(R.id.startingLatitude); 
     startingLongitude = (TextView) findViewById(R.id.startingLongitude); 
     endingLatitude = (TextView) findViewById(R.id.endingLatitude); 
     endingLongitude = (TextView) findViewById(R.id.endingLongitude); 
     myDistance = (TextView) findViewById(R.id.distance); 
     myLogOut = (TextView) findViewById(R.id.logOut); 

     if (location != null) { 
      sLatitude = location.getLatitude(); 
      sLongitude = location.getLongitude(); 

     } 

     updateWithNewLocation(location); 

     locationManager.requestLocationUpdates(provider, 1000, 2, 
       locationListener); 

    } 

    private final LocationListener locationListener = new LocationListener() { 
     @Override 
     public void onLocationChanged(Location location) { 
      updateWithNewLocation(location); 
     } 

     @Override 
     public void onProviderDisabled(String provider) { 
      updateWithNewLocation(null); 
     } 

     @Override 
     public void onProviderEnabled(String provider) { 
     } 

     @Override 
     public void onStatusChanged(String provider, int status, Bundle extras) { 
     } 
    }; 

    private void updateWithNewLocation(Location location) { 

     if (location != null) { 
      latitude = location.getLatitude(); 
      longitude = location.getLongitude(); 

      eLatitude = location.getLatitude(); 
      eLongitude = location.getLongitude(); 
      distance = distance(sLatitude, eLatitude, sLongitude, eLongitude, 
        el1, el2); 

      Geocoder gc = new Geocoder(this, Locale.getDefault()); 
      try { 

       List<Address> addresses = gc.getFromLocation(latitude, 
         longitude, 1); 
       StringBuilder sb = new StringBuilder(); 
       if (addresses.size() > 0) { 
        Address address = addresses.get(0); 

        for (int i = 0; i < address.getMaxAddressLineIndex(); i++) 
         sb.append(address.getAddressLine(i)).append("\n"); 
        sb.append(address.getLocality()).append("\n"); 
        sb.append(address.getPostalCode()).append("\n"); 
        sb.append(address.getCountryName()); 
       } 
       addressString = sb.toString(); 
      } catch (IOException e) { 
      } 
     } else { 
      latLongString = "No location found"; 
     } 

     myLocationText.setText(latLongString); 
     myLatitude.setText("Latitude: " + latitude); 
     myLongitude.setText("Longitude: " + longitude); 
     myAddress.setText(addressString); 
     startingLatitude.setText("Starting latitude: " + sLatitude); 
     startingLongitude.setText("Starting longitude: " + sLongitude); 
     endingLatitude.setText("Last latitude: " + eLatitude); 
     endingLongitude.setText("Last longitude: " + eLongitude); 
     myDistance.setText("Your distance to starting point: " + distance); 

    } 

    public static double distance(double lat1, double lat2, double lon1, 
      double lon2, double el1, double el2) { 

     final int R = 6371; // Radius of the earth 

     double latDistance = Math.toRadians(lat2 - lat1); 
     double lonDistance = Math.toRadians(lon2 - lon1); 
     double a = Math.sin(latDistance/2) * Math.sin(latDistance/2) 
       + Math.cos(Math.toRadians(lat1)) 
       * Math.cos(Math.toRadians(lat2)) * Math.sin(lonDistance/2) 
       * Math.sin(lonDistance/2); 
     double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)); 
     double distance = R * c * 1000; // convert to meters 

     double height = el1 - el2; 

     distance = Math.pow(distance, 2) + Math.pow(height, 2); 
     return Math.sqrt(distance); 
    } 

} 

Answer 1

是的，你可以使用GoogleApiClient獲取用戶的位置，它會照顧一切爲您帶來任何其他建議，最好的做法在android系統使用GoogleApiClient對於位置，因爲它使用最後已知的位置，因爲它的出發點和它共享位置數據，它在設備

這裏所有的應用程序之間的收集是一些基本的代碼邏輯，讓你開始

public class MainActiviy extend Activity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener { 

     @Override 
      protected void onStart() { 
       super.onStart(); 
        mGoogleApiClient.connect(); 
      } 

      @Override 
      protected void onStop() { 
       if(mGoogleApiClient.isConnected()){ 
        mGoogleApiClient.disconnect(); 
       } 
     } 

     @Override 
      public void onConnected(@Nullable Bundle bundle) { 
       LocationRequest mLocationRequest = LocationRequest.create(); 
       mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); 
       mLocationRequest.setInterval(1000);//REQUEST_LOCATION_INTERVAL 
       if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 



        if (ActivityCompat.shouldShowRequestPermissionRationale(
          this, 
          Manifest.permission.ACCESS_FINE_LOCATION)) { 

         AlertDialog.Builder builder = new AlertDialog.Builder(this); 
         builder.setMessage(R.string.permission_prompt_location); 
         builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() { 
          @Override 
          public void onClick(DialogInterface dialog, int which) { 
           ActivityCompat.requestPermissions(
             MainActivity.this, 
             new String[]{Manifest.permission.ACCESS_FINE_LOCATION, 
               Manifest.permission.ACCESS_COARSE_LOCATION}, 
             REQUEST_LOCATION); 
          } 
         }); 
         builder.create().show(); 
        } else { 
         ActivityCompat.requestPermissions(
           this, 
           new String[]{Manifest.permission.ACCESS_FINE_LOCATION, 
             Manifest.permission.ACCESS_COARSE_LOCATION}, 
           REQUEST_LOCATION); 
        } 



        return; 
       } 
       LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this); 

      } 

    @Override 
     public void onRequestPermissionsResult(
       int requestCode, 
       String[] permissions, 
       int[] grantResults) { 
      if(mGoogleApiClient.isConnected()){ 
       mGoogleApiClient.disconnect(); 
      } 

      mGoogleApiClient.connect(); 


       super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

     } 




@Override 
    public void onLocationChanged(Location location) { 
updateWithNewLocation(location); 
} 

}