在Android中使用GPS獲取當前位置

Question

我現在正在一個項目中工作，我想要獲取使用gps的用戶的當前位置。我讀過很多教程並試圖編寫代碼。該代碼在模擬器中運行良好。每當我使用DDMS發送latittude和longitude時，仿真器都會檢測到。主要問題是它不適用於真實的設備。雖然，我嘗試過的設備具有互聯網接入功能，並且GPS已打開。我已將所需的權限添加到清單文件。

public class MainActivity extends Activity { 

TextView lat; 
TextView lon; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    lat=(TextView)findViewById(R.id.textView2); 
    lon=(TextView)findViewById(R.id.textView4); 
    LocationManager lm=(LocationManager)getSystemService(Context.LOCATION_SERVICE); 
    LocationListener ll=new myLocationListener(); 
    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0, ll); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 
    class myLocationListener implements LocationListener{ 

@Override 
public void onLocationChanged(Location location) { 
    // TODO Auto-generated method stub 
    if(location!=null){ 
     double pLat=location.getLatitude(); 
     double pLong=location.getLongitude(); 
     lat.setText(Double.toString(pLat)); 
     lon.setText(Double.toString(pLong)); 
    } 
} 

@Override 
public void onProviderDisabled(String provider) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void onProviderEnabled(String provider) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void onStatusChanged(String provider, int status, Bundle extras) { 
    // TODO Auto-generated method stub 

} 

} 
} 

清單文件

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

允許我需要幫助，請。

Answer 1

GPSTracker gps = new GPSTracker(this); 
double latitude = gps.getLatitude(); 
double longitude = gps.getLongitude(); 

使用該GPS服務：

import android.app.AlertDialog; 
import android.app.Service; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.Intent; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.os.IBinder; 
import android.provider.Settings; 
import android.util.Log; 

public class GPSTracker extends Service implements LocationListener { 

    private final Context mContext; 

    // flag for GPS status 
    boolean isGPSEnabled = false; 

    // flag for network status 
    boolean isNetworkEnabled = false; 

    // flag for GPS status 
    boolean canGetLocation = false; 

    Location location; // location 
    double latitude; // latitude 
    double longitude; // longitude 

    // The minimum distance to change Updates in meters 
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters 

    // The minimum time between updates in milliseconds 
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute 

    // Declaring a Location Manager 
    protected LocationManager locationManager; 

    public GPSTracker(Context context) { 
     this.mContext = context; 
     getLocation(); 
    } 

    public Location getLocation() { 
     try { 
      locationManager = (LocationManager) mContext 
        .getSystemService(LOCATION_SERVICE); 

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

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


      if (!isGPSEnabled && !isNetworkEnabled) { 
       // no network provider is enabled 
      } else { 
       this.canGetLocation = true; 
       if (isNetworkEnabled) { 
        locationManager.requestLocationUpdates(
          LocationManager.NETWORK_PROVIDER, 
          MIN_TIME_BW_UPDATES, 
          MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
        Log.d("Network", "Network"); 
        if (locationManager != null) { 
         location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 
         if (location != null) { 
          latitude = location.getLatitude(); 
          longitude = location.getLongitude(); 
         } 
        } 
       } 
       // if GPS Enabled get lat/long using GPS Services 
       if (isGPSEnabled) { 
        if (location == null) { 
         locationManager.requestLocationUpdates(
           LocationManager.GPS_PROVIDER, 
           MIN_TIME_BW_UPDATES, 
           MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
         Log.d("GPS Enabled", "GPS Enabled"); 
         if (locationManager != null) { 
          location = locationManager 
            .getLastKnownLocation(LocationManager.GPS_PROVIDER); 
          if (location != null) { 
           latitude = location.getLatitude(); 
           longitude = location.getLongitude(); 
          } 
         } 
        } 
       } 
      } 

     } catch (Exception e) { 
     } 
     return location; 
    } 

    /** 
    * Stop using GPS listener Calling this function will stop using GPS in your 
    * app. 
    * */ 
    public void stopUsingGPS() { 
     if (locationManager != null) { 
      locationManager.removeUpdates(GPSTracker.this); 
     } 
    } 

    /** 
    * Function to get latitude 
    * */ 
    public double getLatitude() { 
     if (location != null) { 
      latitude = location.getLatitude(); 
     } 
     // return latitude 
     return latitude; 
    } 

    /** 
    * Function to get longitude 
    * */ 
    public double getLongitude() { 
     if (location != null) { 
      longitude = location.getLongitude(); 
     } 

     // return longitude 
     return longitude; 
    } 

    /** 
    * Function to check GPS/wifi enabled 
    * 
    * @return boolean 
    * */ 
    public boolean canGetLocation() { 
     return this.canGetLocation; 
    } 

    /** 
    * Function to show settings alert dialog On pressing Settings button will 
    * lauch Settings Options 
    * */ 
    public void showSettingsAlert() { 
     AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext); 

     // Setting DialogHelp Title 
     alertDialog.setTitle("GPS is settings"); 

     // Setting DialogHelp Message 
     alertDialog 
       .setMessage("GPS is not enabled. Do you want to go to settings menu?"); 

     // On pressing Settings button 
     alertDialog.setPositiveButton("Settings", 
       new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int which) { 
         Intent intent = new Intent(
           Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
         mContext.startActivity(intent); 
        } 
       }); 

     // on pressing cancel button 
     alertDialog.setNegativeButton("Cancel", 
       new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int which) { 
         dialog.cancel(); 
        } 
       }); 

     // Showing Alert Message 
     alertDialog.show(); 
    } 

    @Override 
    public void onLocationChanged(Location location) { 
     float bestAccuracy = -1f; 
     if (location.getAccuracy() != 0.0f 
      && (location.getAccuracy() < bestAccuracy) || bestAccuracy == -1f) { 
       locationManager.removeUpdates(this); 
     } 
     bestAccuracy = location.getAccuracy(); 
    } 

    @Override 
    public void onProviderDisabled(String provider) { 
    } 

    @Override 
    public void onProviderEnabled(String provider) { 
    } 

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

    @Override 
    public IBinder onBind(Intent arg0) { 
     return null; 
    } 

    public float getAccurecy() 
    { 
     return location.getAccuracy(); 
    } 

} 

Answer 2

嘗試這樣。你應該記住，本地化的東西需要啓動GPS，它需要一些時間。在那個班裏，我用一些延遲來解決本地化問題，因爲GPS組件應該有時間開始。

public class MyBestLocation { 
    LocationListener locationListenerGps = new LocationListener() { 
     @Override 
     public void onLocationChanged(Location location) { 
      locationResult.gotLocation(location); 
      lm.removeUpdates(this); 
      lm.removeUpdates(locationListenerNetwork); 
     } 

     @Override 
     public void onProviderDisabled(String provider) { 
     } 

     @Override 
     public void onProviderEnabled(String provider) { 
     } 

     @Override 
     public void onStatusChanged(String provider, int status, Bundle extras) { 
     } 
    }; 
    LocationListener locationListenerNetwork = new LocationListener() { 
     @Override 
     public void onLocationChanged(Location location) { 
      locationResult.gotLocation(location); 
      lm.removeUpdates(this); 
      lm.removeUpdates(locationListenerGps); 
     } 

     @Override 
     public void onProviderDisabled(String provider) { 
     } 

     @Override 
     public void onProviderEnabled(String provider) { 
     } 

     @Override 
     public void onStatusChanged(String provider, int status, Bundle extras) { 
     } 
    }; 
    //delay in seconds 
    private int DELAY = 1; 
    private Timer timer1; 
    private LocationManager lm; 
    private LocationResult locationResult; 
    private boolean gps_enabled = false; 
    private boolean network_enabled = false; 
    private ScheduledExecutorService scheduler; 
    private ScheduledFuture scheduledFuture; 

    public boolean getLocation(Context context, LocationResult result) { 
     // 
     locationResult = result; 
     if (lm == null) 
      lm = (LocationManager) context 
        .getSystemService(Context.LOCATION_SERVICE); 

     // checking weather providers are aviliable 
     try { 
      gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER); 
     } catch (Exception ex) { 
     } 
     try { 
      network_enabled = lm 
        .isProviderEnabled(LocationManager.NETWORK_PROVIDER); 
     } catch (Exception ex) { 
     } 

     // 
     if (!gps_enabled && !network_enabled) 
      return false; 

     if (gps_enabled) 
      lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, 
        locationListenerGps); 
     if (network_enabled) 
      lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, 
        locationListenerNetwork); 
     //---------------------- 
     // async executor method upgrade 
     timer1 = new Timer(); 
     timer1.schedule(new GetLastLocation(), DELAY*2000); 
     // ---------------- 

     // 
     /* scheduler = Executors.newSingleThreadScheduledExecutor(); 
     scheduler.schedule(new GetLastLocation(), DELAY, TimeUnit.SECONDS);*/ 
     return true; 
    } 

    // Timer for the latest location 

    public static abstract class LocationResult { 
     public abstract void gotLocation(Location location); 
    } 

    /** 
    * 
    * 
    * @author rafik991 
    */ 
    class GetLastLocation extends TimerTask { 
     @Override 
     public void run() { 


      lm.removeUpdates(locationListenerGps); 
      lm.removeUpdates(locationListenerNetwork); 

      Location net_loc = null, gps_loc = null; 
      if (gps_enabled) 
       gps_loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
      if (network_enabled) 
       net_loc = lm 
         .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 

      // if there are both values use the latest one 
      if (gps_loc != null && net_loc != null) { 
       if (gps_loc.getTime() > net_loc.getTime()) 
        locationResult.gotLocation(gps_loc); 
       else 
        locationResult.gotLocation(net_loc); 

       return; 
      } 

      if (gps_loc != null) { 
       locationResult.gotLocation(gps_loc); 

       return; 
      } 
      if (net_loc != null) { 
       locationResult.gotLocation(net_loc); 

       return; 
      } 
//   locationResult.gotLocation(null); 
     } 

    } 

}