android - requestLocationUpdates 在位置变化实际上增加了一次时调用了很多次

Question

我正在发送纬度、经度和位置名称以保存在服务器上....问题是当我第一次运行我的应用程序时它正常并保存以上数据一次...当我关闭我的应用程序并且模拟器正在运行时并且 eclipse 也再次启动我的应用程序然后它保存以上数据 2 次.....同样当我关闭并重新启动我的应用程序时它增加 1...我不知道为什么它调用 requestLocationUpdates() 很多次...没有发送到服务器它工作正常..任何关于这个的想法请帮助我...

向服务器发送数据..这个功能在send.java类中实现

public String postData(List<? extends NameValuePair> nameValuePairs, String wurl){

     // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(wurl); 
    try {

        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
        // Execute HTTP Post Request
        HttpResponse response = httpclient.execute(httppost);

        InputStream is = response.getEntity().getContent();
        BufferedInputStream bis = new BufferedInputStream(is);
        ByteArrayBuffer baf = new ByteArrayBuffer(20);
        int current = 0;
        while((current = bis.read()) != -1){
            baf.append((byte)current);
        } 
        /* Convert the Bytes read to a String. */
        text = new String(baf.toByteArray());

    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block
    }
    return text;

}

onlocationchaned 函数在实现 LocationListener 的 location.java 类中，并在 onlocationchanged 中调用上面的函数

public void onLocationChanged(android.location.Location loc) {

    String response;
    latitude = loc.getLatitude();
    longitude = loc.getLongitude();

    // Changing type double to string for sending 
    lati = Double.toString(latitude);
    logi = Double.toString(longitude);

        String Text = "My current location is: " + 
                  " Latitude = " + Location.lati + 
                  " Longitude = "+ Location.logi;
        Toast.makeText(c,  Text , Toast.LENGTH_LONG).show();
        Log.d("lat", "Changed");

        locationName = getAddress(latitude, longitude);

        // Add location related data
        List<BasicNameValuePair> locationNameValuePair = new ArrayList<BasicNameValuePair>(4);
        locationNameValuePair.add(new BasicNameValuePair("latitude", lati));
        locationNameValuePair.add(new BasicNameValuePair("longitude", logi));
        locationNameValuePair.add(new BasicNameValuePair("locName", locationName));

        response = con.postData(locationNameValuePair, wurl);
        Toast.makeText(c, response, Toast.LENGTH_LONG).show();

        Log.v("IGA", "Address " + locationName);
        Toast.makeText(c, locationName, Toast.LENGTH_LONG).show();
}


 public String getAddress(double lat, double lng) {
    Geocoder geocoder = new Geocoder(c, Locale.getDefault());
    try {
        List<Address> addresses = geocoder.getFromLocation(lat, lng, 1);
        Address obj = addresses.get(0);
        //String add = obj.getAddressLine(0);
        String add = obj.getThoroughfare();
        add = add + ", " + obj.getSubLocality();
        add = add + ", " + obj.getLocality();
        add = add + ", " + obj.getCountryName();

         return add;

    } catch (IOException e) {
        e.printStackTrace();
        Toast.makeText(c, e.getMessage(), Toast.LENGTH_LONG).show();
    } catch (IndexOutOfBoundsException e) {
        e.printStackTrace();
        Toast.makeText(c, e.getMessage(), Toast.LENGTH_LONG).show();
    }
    return "";
}

和扩展 MapActivity 的 mainavtivity 中的 locationManager

   protected void onCreate(Bundle savedInstanceState) {

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MapView view = (MapView) findViewById(R.id.themap);
        view.setBuiltInZoomControls(true);


        LocationManager mlocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        Location mylocation = new Location(MainActivity.this);
        mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mylocation);


    }

Answer 1

mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mylocation);

如果您想确保 1000 毫秒已经过去并且客户端在位置更新之间移动了 5 米，则应该是以下内容

LocationListener customLocationListener = new CustomLocationListener();
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 5, customLocationListener);

此外，在您的 Activity 中调用 onPause() 方法

mlocManager .removeUpdates(customLocationListener);

您必须像下面这样实现 CustomLocationListener:

private class CustomeLocationListener implements LocationListener
{
    @Override
    public void onLocationChanged(Location loc)
    {
        // when location changes, add the record in the database, send to server etc...
        double lat = loc.getLatitude();
        double lon = loc.getLongitude();
    }

    @Override
    public void onProviderDisabled(String provider)
    {}

    @Override
    public void onProviderEnabled(String provider)
    {}

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