Gps和網絡狀態來計算位置在建築物內不準確

Question

位置管理器沒有給出建築物內的準確位置數據，它很難一起處理gps和網絡狀態。是否有任何解決這個問題的計算確切的數據比這更好。我想在計程表中使用它。

public Location getLocation() { 
     try { 
      mLocationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE); 

      // getting GPS status 
      boolean isGPSEnabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER); 

      // getting network status 
      boolean isNetworkEnabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER); 

      if (!isGPSEnabled && !isNetworkEnabled) { 
       // no network provider is enabled 
      } else { 
       // First get location from Network Provider 
       if (isNetworkEnabled) { 
        mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
        Log.d("Network", "Network"); 
        if (mLocationManager != null) { 
         location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 
         if (location != null) { 
          lat = location.getLatitude(); 
          lng = location.getLongitude(); 
         } 
        } 
       } 
       //get the location by gps 
       if (isGPSEnabled) { 
        if (location == null) { 
         mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MIN_TIME_BW_UPDATES,MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
         Log.d("GPS Enabled", "GPS Enabled"); 
         if (mLocationManager != null) {location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
          if (location != null) { 
           lat = location.getLatitude(); 
           lng = location.getLongitude(); 
          } 
         } 
        } 
       } 
      } 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     return location; 
    } 

Answer 1

使用Google開發人員開發的融合API與GPS Sensor，Magnetometer，Accelerometer的融合也使用Wifi或單元位置計算或估計位置。它也能夠在建築物內精確地提供位置更新。

package com.example.ashis.gpslocation; 

import android.app.Activity; 
import android.location.Location; 
import android.os.Bundle; 
import android.support.v7.app.ActionBarActivity; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.GooglePlayServicesUtil; 
import com.google.android.gms.common.api.GoogleApiClient; 
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks; 
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener; 
import com.google.android.gms.location.LocationListener; 
import com.google.android.gms.location.LocationRequest; 
import com.google.android.gms.location.LocationServices; 

import java.util.concurrent.Executors; 
import java.util.concurrent.TimeUnit; 

/** 
* Location sample. 
* 
* Demonstrates use of the Location API to retrieve the last known location for a device. 
* This sample uses Google Play services (GoogleApiClient) but does not need to authenticate a user. 
* See https://github.com/googlesamples/android-google-accounts/tree/master/QuickStart if you are 
* also using APIs that need authentication. 
*/ 

public class MainActivity extends Activity implements LocationListener, 
     GoogleApiClient.ConnectionCallbacks, 
     GoogleApiClient.OnConnectionFailedListener { 

    private static final long ONE_MIN = 500; 
    private static final long TWO_MIN = 500; 
    private static final long FIVE_MIN = 500; 
    private static final long POLLING_FREQ = 1000 * 20; 
    private static final long FASTEST_UPDATE_FREQ = 1000 * 5; 
    private static final float MIN_ACCURACY = 1.0f; 
    private static final float MIN_LAST_READ_ACCURACY = 1; 

    private LocationRequest mLocationRequest; 
    private Location mBestReading; 
TextView tv; 
    private GoogleApiClient mGoogleApiClient; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     if (!servicesAvailable()) { 
      finish(); 
     } 

     setContentView(R.layout.activity_main); 
tv= (TextView) findViewById(R.id.tv1); 
     mLocationRequest = LocationRequest.create(); 
     mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); 
     mLocationRequest.setInterval(POLLING_FREQ); 
     mLocationRequest.setFastestInterval(FASTEST_UPDATE_FREQ); 

     mGoogleApiClient = new GoogleApiClient.Builder(this) 
       .addApi(LocationServices.API) 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this) 
       .build(); 


     if (mGoogleApiClient != null) { 
      mGoogleApiClient.connect(); 
     } 
    } 

    @Override 
    protected void onResume() { 
     super.onResume(); 

     if (mGoogleApiClient != null) { 
      mGoogleApiClient.connect(); 
     } 
    } 

    @Override 
    protected void onPause() {d 
     super.onPause(); 

     if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) { 
      mGoogleApiClient.disconnect(); 
     } 
    } 


     tv.setText(location + ""); 
     // Determine whether new location is better than current best 
     // estimate 
     if (null == mBestReading || location.getAccuracy() < mBestReading.getAccuracy()) { 
      mBestReading = location; 


      if (mBestReading.getAccuracy() < MIN_ACCURACY) { 
       LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
      } 
     } 
    } 

    @Override 
    public void onConnected(Bundle dataBundle) { 
     // Get first reading. Get additional location updates if necessary 
     if (servicesAvailable()) { 

      // Get best last location measurement meeting criteria 
      mBestReading = bestLastKnownLocation(MIN_LAST_READ_ACCURACY, FIVE_MIN); 

      if (null == mBestReading 
        || mBestReading.getAccuracy() > MIN_LAST_READ_ACCURACY 
        || mBestReading.getTime() < System.currentTimeMillis() - TWO_MIN) { 

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

       //Schedule a runnable to unregister location listeners 

        @Override 
        public void run() { 
         LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, MainActivity.this); 

        } 

       }, ONE_MIN, TimeUnit.MILLISECONDS); 

      } 

     } 
    } 

    @Override 
    public void onConnectionSuspended(int i) { 

    } 


    private Location bestLastKnownLocation(float minAccuracy, long minTime) { 
     Location bestResult = null; 
     float bestAccuracy = Float.MAX_VALUE; 
     long bestTime = Long.MIN_VALUE; 

     // Get the best most recent location currently available 
     Location mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient); 
     //tv.setText(mCurrentLocation+""); 
     if (mCurrentLocation != null) { 
      float accuracy = mCurrentLocation.getAccuracy(); 
      long time = mCurrentLocation.getTime(); 

      if (accuracy < bestAccuracy) { 
       bestResult = mCurrentLocation; 
       bestAccuracy = accuracy; 
       bestTime = time; 
      } 
     } 

     // Return best reading or null 
     if (bestAccuracy > minAccuracy || bestTime < minTime) { 
      return null; 
     } 
     else { 
      return bestResult; 
     } 
    } 

    @Override 
    public void onConnectionFailed(ConnectionResult connectionResult) { 

    } 

    private boolean servicesAvailable() { 
     int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this); 

     if (ConnectionResult.SUCCESS == resultCode) { 
      return true; 
     } 
     else { 
      GooglePlayServicesUtil.getErrorDialog(resultCode, this, 0).show(); 
      return false; 
     } 
    } 
}