Question

我的方案是每隔20秒获取移动设备的lat和long，并使用asmx web服务将lat，long值放在数据库中。我编写了一个实现位置监听器的服务，并且能够从中获取lat long值服务

该服务的实施如下。我的GpsTracker服务。

public class GPSTracker extends Service implements LocationListener {

    // Get Class Name
    private static String TAG = GPSTracker.class.getName();

    private final Context mContext;

    // flag for GPS Status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS Tracking is enabled 
    boolean isGPSTrackingEnabled = false;

    Location location;
    double latitude;
    double longitude;

    // How many Geocoder should return our GPSTracker
    int geocoderMaxResults = 1;

    // 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 *20* 1; //5 seconds

    // Declaring a Location Manager
    protected LocationManager locationManager;

    // Store LocationManager.GPS_PROVIDER or LocationManager.NETWORK_PROVIDER information
    private String provider_info;

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

    /**
     * Try to get my current location by GPS or Network Provider
     */
    public void 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);

            // Try to get location if you GPS Service is enabled
            if (isGPSEnabled) {
                this.isGPSTrackingEnabled = true;

                Log.d(TAG, "Application use GPS Service");

                /*
                 * This provider determines location using
                 * satellites. Depending on conditions, this provider may take a while to return
                 * a location fix.
                 */

                provider_info = LocationManager.GPS_PROVIDER;

            } else if (isNetworkEnabled) { // Try to get location if you Network Service is enabled
                this.isGPSTrackingEnabled = true;

                Log.d(TAG, "Application use Network State to get GPS coordinates");

                /*
                 * This provider determines location based on
                 * availability of cell tower and WiFi access points. Results are retrieved
                 * by means of a network lookup.
                 */
                provider_info = LocationManager.NETWORK_PROVIDER;

            } 

            // Application can use GPS or Network Provider
            if (!provider_info.isEmpty()) {
                locationManager.requestLocationUpdates(
                    provider_info,
                    MIN_TIME_BW_UPDATES,
                    MIN_DISTANCE_CHANGE_FOR_UPDATES, 
                    this
                );

                if (locationManager != null) {
                    location = locationManager.getLastKnownLocation(provider_info);
                    updateGPSCoordinates();
                }
            }
        }
        catch (Exception e)
        {
            //e.printStackTrace();
            Log.e(TAG, "Impossible to connect to LocationManager", e);
        }
    }

    /**
     * Update GPSTracker latitude and longitude
     */
    public void updateGPSCoordinates() {
        if (location != null) {
            latitude = location.getLatitude();
            longitude = location.getLongitude();
        }
    }

    /**
     * GPSTracker latitude getter and setter
     * @return latitude
     */
    public double getLatitude() {
        if (location != null) {
            latitude = location.getLatitude();
        }

        return latitude;
    }

    /**
     * GPSTracker longitude getter and setter
     * @return
     */
    public double getLongitude() {
        if (location != null) {
            longitude = location.getLongitude();
        }

        return longitude;
    }

    /**
     * GPSTracker isGPSTrackingEnabled getter.
     * Check GPS/wifi is enabled
     */
    public boolean getIsGPSTrackingEnabled() {

        return this.isGPSTrackingEnabled;
    }

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



    @Override
    public void onLocationChanged(Location location) {
        latitude=location.getLatitude();
    longitude=location.getLongitude();
    }

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

    @Override
    public void onProviderEnabled(String provider) {
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

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

在我的活动中，点击按钮后我有两个按钮，应启动此服务。但现在我遇到以下问题

1）如果手机进入睡眠模式，服务不会获取lat，long值。

2）如何将lat，long值返回给活动，以便我可以调用将lat，long值放在数据库中的Web服务（另一个应用程序从这里选择这些值）

3）LocationManager.requestlocationupdates函数以不规则的间隔给出lat long值，而不是参数中指定的值

我见过人们使用AlarmManager，但我没有得到正确的用法，因为LocationManager.requestlocationupdates提供了相同的功能。连接到asmx部分非常清楚，我正在使用ksoap jar文件。有没有其他比这更好的。

我也尝试过使用CWAC LocationPoller这是一个很棒的东西，但正如Commonware在之前的帖子中所建议的那样，LocationPoller设计用于更长的轮询时间：一小时，而不是10秒。我已经放弃了继续这个想法。

这是我见过的第一个服务，我是3天前钻研过它的android世界的新手。请帮助!!。期待您宝贵的建议

先谢谢..

定期从服务和更新数据库获取Lat，Long值

0 个答案: