我的位置管理器准確性不高

Question

我的位置管理器准確性有問題。.我需要幫助才能獲得較高的確定性..有時它給出正確的坐標，但是有時卻給出錯誤的提示，例如...當我第一次嘗試時，它給出了正確的坐標然后我再試一次，它給出了錯誤的坐標..就像它給出的坐標是來自另一個城市的坐標...有什么辦法可以解決這個問題？

這是我的代碼。

package com.example.christian.mylocation;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText etLatitude, etLongitude;
    Button btnGetloc;

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

        etLatitude = (EditText) findViewById(R.id.etLatitude);
        etLongitude = (EditText) findViewById(R.id.etLongitude);
        btnGetloc = (Button) findViewById(R.id.btnGetloc);

        btnGetloc.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                LocationManager locationManager = (LocationManager) MainActivity.this.getSystemService(Context.LOCATION_SERVICE);
                LocationListener locationListener = new LocationListener() {
                    @Override
                    public void onLocationChanged(Location location) {
                        String lat = Double.toString(location.getLatitude());
                        String lon = Double.toString(location.getLongitude());

                        etLatitude.setText(lat);
                        etLongitude.setText(lon);
                    }

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

                    }

                    @Override
                    public void onProviderEnabled(String provider) {

                    }

                    @Override
                    public void onProviderDisabled(String provider) {

                    }
                };
                if ((ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED))
                    if ((ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)) {
                        // TODO: Consider calling
                        //    ActivityCompat#requestPermissions
                        // here to request the missing permissions, and then overriding
                        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                        //                                          int[] grantResults)
                        // to handle the case where the user grants the permission. See the documentation
                        // for ActivityCompat#requestPermissions for more details.
                        return;
                    }
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
            }
        });

    }
}

Answer 1

您可能希望最新的位置修復是最准確的。 但是，由於位置定位的准確性各不相同，所以最新的定位並不總是最好的。 您應包括根據多個條件選擇位置定位的邏輯

您需要按照以下步驟操作以提高准確性

• 檢查檢索到的位置是否比以前的估計新得多。
• 檢查該位置要求的精度是好於還是差於先前的估計。
• 檢查新位置來自哪個提供商，並確定您是否更信任它。

一個例子在這里。

private static final int TWO_MINUTES = 1000 * 60 * 2;

/** Determines whether one Location reading is better than the current Location fix
  * @param location  The new Location that you want to evaluate
  * @param currentBestLocation  The current Location fix, to which you want to compare the new one
  */
protected boolean isBetterLocation(Location location, Location currentBestLocation) {
    if (currentBestLocation == null) {
        // A new location is always better than no location
        return true;
    }

    // Check whether the new location fix is newer or older
    long timeDelta = location.getTime() - currentBestLocation.getTime();
    boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
    boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
    boolean isNewer = timeDelta > 0;

    // If it's been more than two minutes since the current location, use the new location
    // because the user has likely moved
    if (isSignificantlyNewer) {
        return true;
    // If the new location is more than two minutes older, it must be worse
    } else if (isSignificantlyOlder) {
        return false;
    }

    // Check whether the new location fix is more or less accurate
    int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
    boolean isLessAccurate = accuracyDelta > 0;
    boolean isMoreAccurate = accuracyDelta < 0;
    boolean isSignificantlyLessAccurate = accuracyDelta > 200;

    // Check if the old and new location are from the same provider
    boolean isFromSameProvider = isSameProvider(location.getProvider(),
            currentBestLocation.getProvider());

    // Determine location quality using a combination of timeliness and accuracy
    if (isMoreAccurate) {
        return true;
    } else if (isNewer && !isLessAccurate) {
        return true;
    } else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
        return true;
    }
    return false;
}

/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
    if (provider1 == null) {
      return provider2 == null;
    }
    return provider1.equals(provider2);
}

編輯：執行任何步驟之前，您必須在清單中具有權限

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.google.android.gms.location.sample.basiclocationsample" >

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

ACCESS_FINE_LOCATION比限於城市級別的ACCESS_COURSE_LOCATION更精確。