在某些安卓手机中无法获得准确的位置

Question

我使用了下面的代码。它工作正常，但在 Redme、Asus 等某些设备中无法获得准确的位置。它显示我离当前位置大约 20 公里远。没有找到问题所在，有人有想法请分享想法。提前致谢。

public class Currentlocation 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
public 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;

SetOnLocationFoundListner OLF;

public interface SetOnLocationFoundListner {
    public void onLocationFound(Location location, boolean getLocRegularly, GoogleMap gmap);
}

public Currentlocation(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;
            // First get location from Network Provider
            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) {
        locationManager.removeUpdates(Currentlocation.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;
}

@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub

}

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

}

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

}

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

}

@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

/**
 * Function to show settings alert dialog On pressing Settings button will
 * lauch Settings Options
 */

}

Answer 1

你不能指望手机既不总是有一个有效的“最后已知位置”也不以微秒为单位定义它的位置。

您首先致电requestLocationUpdates()，然后立即致电getLastKnownLocation()。手机没有时间确定/更新“最后已知位置”。此外，现在当你打电话给getLocation() 时，你总是一次又一次地打电话给requestLocationUpdates()。当您想开始接收位置更新时，只需调用一次即可。

只需订阅一次即可接收位置更新，并始终在回调中获得最新位置，该回调会稍有延迟。您已经有了空的 onLocationChanged() 方法。那就是回调方法。只需让它处理位置更新。

如果您不想收到任何进一步的更新，当然可以在onLocationChanged() 回调中收到最新的位置后致电removeUpdates() 或removeLocationUpdates()。

一些有用的 Stackoverflow 讨论：

How to get location that isn't out of date?

Android: getLastKnownLocation out-of-date - how to force location refresh?

Android - Reliably getting the current location