想用GPS经纬度建立考勤跟踪系统 [英] Want to build attendance tracking system with GPS latitude and longitude

问题描述

建立一个算法来找到一个由四组lat长度构成的多边形...并且通过当前lat来查找一组lat长是否属于那个多边形。但目前的经纬度并不准确。在android中使用GPS和网络系统来跟踪当前的经纬度。

  public void find current_lat_long（）{
 com .example.gps.AppLocationService appLocationService = new com.example.gps.AppLocationService（
 Map_Location.this）; 
位置gpsLocation = appLocationService 
 .getLocation（LocationManager.GPS_PROVIDER）; 
位置nwLocation = appLocationService 
 .getLocation（LocationManager.NETWORK_PROVIDER）; 
 if（gpsLocation！= null）{
 latitude_gps_calc_lat = gpsLocation.getLatitude（）; 
 longitude_gpa_calc_lng = gpsLocation.getLongitude（）; 
 constant.lat = String.valueOf（gpsLocation.getLatitude（））; 
 constant.longitude = String.valueOf（gpsLocation.getLongitude（））; 
 constant.flag_gps = false; 
字符串latlong_gps = String.valueOf（gpsLocation.getLatitude（））+ String.valueOf（gpsLocation.getLongitude（））; 
 // lat1_string = constant.lat; 
 // long_1_string = constant.longitude; 
 
 lat4_string = constant.lat; 
 long_4_string = constant.longitude; 
 
返回true; 
} 
 else if（nwLocation！= null）
 {
 latitude_network_provider = nwLocation.getLatitude（）; 
 longitude_network_provider = nwLocation.getLongitude（）; 
 constant.flag_network = false; 
 latlong__network_provider = String.valueOf（latitude_network_provider）+ String.valueOf（longitude_network_provider）; 
 
 constant.lat = String.valueOf（latitude_network_provider）; 
 constant.longitude = String.valueOf（longitude_network_provider）; 
 lat4.setText（constant.lat + constant.longitude）; 
 lat4_string = constant.lat; 
 long_4_string = constant.longitude; 
 
返回true; 
 
 
} 
  

}

请帮助找到准确的经纬度，以便跟踪长期属于特定多边形的纬度。

解决方案

您可以使用以下代码查找位置：

声明变量：

  LocationManager lm; 
 LocationListener ll; 
  

开始位置侦听器：

  lm =（LocationManager）getActivity（）。getSystemService（Context.LOCATION_SERVICE）; 
 ll = new startLocationListener（）; 
 lm.requestLocationUpdates（LocationManager.GPS_PROVIDER，0，0，ll）; 
  

位置侦听器：

  class gpsLocationListener implements LocationListener {
 
 public void onLocationChanged（Location location）{
 if（location！= null）{
 String latitude = location.getLatitude（）; 
 String longitude = location.getLongitude（）; 
 
 
 $ b $ public void onProviderDisabled（String provider）{
} 
 
 public void onProviderEnabled（String provider）{
} 
 
 public void onStatusChanged（String provider，int status，Bundle extras）{
} 
 
} 
  

在找到位置后，您可以停止使用onLocationChanged中的侦听器：

  lm.removeUpdates（ll）; 
 lm = null; 
  

build a algorithm to find a polygon build by four sets of lat long.. and passing current lat long to find whether a set of lat long belong to that polygon or not. But the the current latiitude and longitude is not accurate . in android using GPS and network system to tracking current latitude and longitude.

 public void find current_lat_long(){
com.example.gps.AppLocationService appLocationService = new com.example.gps.AppLocationService(
            Map_Location.this);
    Location gpsLocation = appLocationService
            .getLocation(LocationManager.GPS_PROVIDER);
    Location nwLocation = appLocationService
            .getLocation(LocationManager.NETWORK_PROVIDER);
    if (gpsLocation != null) {
        latitude_gps_calc_lat = gpsLocation.getLatitude();
        longitude_gpa_calc_lng = gpsLocation.getLongitude();
        constant.lat=String.valueOf(gpsLocation.getLatitude());
        constant.longitude=String.valueOf(gpsLocation.getLongitude());
        constant.flag_gps=false;
        String latlong_gps = String.valueOf(gpsLocation.getLatitude())+String.valueOf( gpsLocation.getLongitude());
//       lat1_string=constant.lat;
//          long_1_string=constant.longitude;

           lat4_string=constant.lat;
            long_4_string=constant.longitude;

        return true;
    }
    else if (nwLocation != null)
        {
                latitude_network_provider = nwLocation.getLatitude();
                longitude_network_provider = nwLocation.getLongitude();
                constant.flag_network=false;
                latlong__network_provider =String.valueOf(latitude_network_provider)+String.valueOf(longitude_network_provider);

                constant.lat=String.valueOf(latitude_network_provider);
                constant.longitude=String.valueOf(longitude_network_provider);
                   lat4.setText(constant.lat+constant.longitude);
                   lat4_string=constant.lat;
                    long_4_string=constant.longitude;

            return true;


    } 

}

Please help to find accurate lat long to tracking that lat long belong to the particular polygon.

解决方案

You can find location using the below code:

Declare the variable:

LocationManager lm;
LocationListener ll;

Start Location listener :

    lm = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
    ll = new startLocationListener();
    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,ll);

Location listener:

class gpsLocationListener implements LocationListener {

    public void onLocationChanged(Location location) {
        if (location != null) {
            String latitude =  location.getLatitude();
            String longitude = location.getLongitude();                
        }
    }

    public void onProviderDisabled(String provider) {
    }

    public void onProviderEnabled(String provider) {
    }

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

}

After finding location you can stop listener using this in onLocationChanged:

 lm.removeUpdates(ll);
 lm = null;

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