我的位置管理器准确性不高

Question

我的位置管理器准确性有问题。.我需要帮助才能获得较高的确定性..有时它给出正确的坐标，但是有时却给出错误的提示，例如...当我第一次尝试时，它给出了正确的坐标然后我再试一次，它给出了错误的坐标..就像它给出的坐标是来自另一个城市的坐标...有什么办法可以解决这个问题？

这是我的代码。

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复是最准确的。 但是，由于位置定位的准确性各不相同，所以最新的定位并不总是最好的。 您应包括根据多个条件选择位置定位的逻辑

您需要按照以下步骤操作以提高准确性

• 检查检索到的位置是否比以前的估计新得多。
• 检查该位置要求的精度是好于还是差于先前的估计。
• 检查新位置来自哪个提供商，并确定您是否更信任它。

一个例子在这里。

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);
}

编辑：执行任何步骤之前，您必须在清单中具有权限

<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比限于城市级别的ACCESS_COURSE_LOCATION更精确。