位置管理器最小位移与高精度android

Posted 2023-04-14

【中文标题】位置管理器最小位移与高精度android

【英文标题】：Location Manager smallest displacement with high accuracy android

【发布时间】：2014-12-10 11:16:00

【问题描述】：

我正在尝试实现一个使用用户当前位置的应用程序。由于我需要 PRIORITY_HIGH_ACCURACY，我想在用户不移动时停止这些 gps 更新。目前我的代码如下所示。

mLocationClient = new LocationClient(this, this, this);
mLocationClient.connect();

并在连接后执行以下操作。

Location location = mLocationClient.getLastLocation();
locationrequest = LocationRequest.create(); 
locationrequest.setSmallestDisplacement(10f);
locationrequest.setInterval(10*1000);
locationrequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationClient.requestLocationUpdates(locationrequest, this);

问题是 minimumDisplacement 根本不起作用。我试图删除：

locationrequest.setInterval(10*1000);

但在我删除它后，我没有收到任何其他位置更新。谁能告诉我我做错了什么？

【参考方案1】：

只有使用 GPS 才能实现高精度。您需要从 gps 获取位置更新，而不是从 newtwork 提供商处获取。

即使您从 GPS 获取值，也请确保您是在建筑物外测试应用程序。如果您在建筑物内，有时您不会收到位置更改更新。

我知道这听起来可能很傻，但我遇到了这个问题，如果我在开放式顶部测试我的代码，它对我有用。

我不确定这是否有效，但如果你有同样的感觉，值得一试。

供您参考，我正在使用以下类来获取位置更新。

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) 
            e.printStackTrace();
        

        return location;
    

    /**
     * Stop using GPS listener
     * Calling this function will stop using GPS in your app
     * */
    public void stopUsingGPS()
        if(locationManager != null)
            Log.i("GPSTracker:", "Removing Loc Updates");
            locationManager.removeUpdates(GPSTracker.this);
        
        //StopService
        Log.i("GPSTracker:", "Stopping GPS Service");
        stopSelf();
    

    /**
     * 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 Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog 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) 
                //Stop Service
                stopSelf();
                dialog.cancel();
            
        );

        // Showing Alert Message
        alertDialog.show();
    

    @Override
    public void onLocationChanged(Location location) 
    

    @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;
    

谢谢。

【讨论】：

我试过你的示例代码。它正在工作。但问题是在固定位置获取位置更新并绘制路线。你能告诉如何在固定位置停止位置更新吗？