在Android 8.1或更低的版本上，用户可以开启“省电”模式 >位置>模式>节电。 这种模式只使用WiFi、蓝牙或移动数据，而不是GPS来确定用户的位置。

这就是为什么你必须检查网络提供者是否已启用，locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)是否不够。

如果你正在使用androidx，这段代码将检查你正在运行的SDK版本，并调用相应的提供商:

public boolean isLocationEnabled(Context context) {
    LocationManager manager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    return manager != null && LocationManagerCompat.isLocationEnabled(manager);
}

我使用下面的代码来检查:

public static boolean isLocationEnabled(Context context) {
    int locationMode = 0;
    String locationProviders;

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT){
        try {
            locationMode = Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.LOCATION_MODE);

        } catch (SettingNotFoundException e) {
            e.printStackTrace();
            return false;
        }

        return locationMode != Settings.Secure.LOCATION_MODE_OFF;

    }else{
        locationProviders = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
        return !TextUtils.isEmpty(locationProviders);
    }


} 

private boolean isGpsEnabled()
{
    LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
    return service.isProviderEnabled(LocationManager.GPS_PROVIDER)&&service.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}

要在android谷歌地图中获取当前地理位置，您应该打开设备位置选项。要检查位置是否打开，您可以从onCreate()方法简单地调用此方法。

private void checkGPSStatus() {
    LocationManager locationManager = null;
    boolean gps_enabled = false;
    boolean network_enabled = false;
    if ( locationManager == null ) {
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    }
    try {
        gps_enabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    } catch (Exception ex){}
    try {
        network_enabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
    } catch (Exception ex){}
    if ( !gps_enabled && !network_enabled ){
        AlertDialog.Builder dialog = new AlertDialog.Builder(MyActivity.this);
        dialog.setMessage("GPS not enabled");
        dialog.setPositiveButton("Ok", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                //this will navigate user to the device location settings screen
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(intent);
            }
        });
        AlertDialog alert = dialog.create();
        alert.show();
    }
}

您可以使用此代码引导用户到设置，在那里他们可以启用GPS:

    locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    if( !locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) ) {
        new AlertDialog.Builder(context)
            .setTitle(R.string.gps_not_found_title)  // GPS not found
            .setMessage(R.string.gps_not_found_message) // Want to enable?
            .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialogInterface, int i) {
                    owner.startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                }
            })
            .setNegativeButton(R.string.no, null)
            .show();
    }

public class LocationUtil {
private static final String TAG = LocationUtil.class.getSimpleName();

public static LocationManager getLocationManager(final Context context) {
    return (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
}

public static boolean isNetworkProviderEnabled(final Context context) {
    return getLocationManager(context).isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}

public static boolean isGpsProviderEnabled(final Context context) {
    return getLocationManager(context).isProviderEnabled(LocationManager.GPS_PROVIDER);
}

// Returns true even if the location services are disabled. Do not use this method to detect location services are enabled.
private static boolean isPassiveProviderEnabled(final Context context) {
    return getLocationManager(context).isProviderEnabled(LocationManager.PASSIVE_PROVIDER);
}

public static boolean isLocationModeOn(final Context context) throws Exception {
    int locationMode = Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.LOCATION_MODE);
    return locationMode != Settings.Secure.LOCATION_MODE_OFF;
}

public static boolean isLocationEnabled(final Context context) {
    try {
        return isNetworkProviderEnabled(context) || isGpsProviderEnabled(context)  || isLocationModeOn(context);
    } catch (Exception e) {
        Log.e(TAG, "[isLocationEnabled] error:", e);
    }
    return false;
}

public static void gotoLocationSettings(final Activity activity, final int requestCode) {
    Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
    activity.startActivityForResult(intent, requestCode);
}

public static String getEnabledProvidersLogMessage(final Context context){
    try{
        return "[getEnabledProvidersLogMessage] isNetworkProviderEnabled:"+isNetworkProviderEnabled(context) +
                ", isGpsProviderEnabled:" + isGpsProviderEnabled(context) +
                ", isLocationModeOn:" + isLocationModeOn(context) +
                ", isPassiveProviderEnabled(ignored):" + isPassiveProviderEnabled(context);
    }catch (Exception e){
        Log.e(TAG, "[getEnabledProvidersLogMessage] error:", e);
        return "provider error";
    }
}

}

使用isLocationEnabled方法检测位置服务是否已启用。

https://github.com/Polidea/RxAndroidBle/issues/327#页面将提供更多信息为什么不使用被动提供程序，而是使用定位模式。