使用javascript獲取GPS位置

Question

我正在使用平板電腦，在html應用程序上工作，希望在不使用任何網絡連接的情況下獲取GPS位置。 請給我簡單的方法。

Answer 1

使用JS，你可以得到它像這樣

<script> 
    var x = document.getElementById("demo"); 
    function getLocation() { 
    if (navigator.geolocation) { 
     navigator.geolocation.getCurrentPosition(showPosition); 
    } else { 
     x.innerHTML = "Geolocation is not supported by this browser."; 
    } 
} 
function showPosition(position) { 
    x.innerHTML = "Latitude: " + position.coords.latitude + "<br>Longitude: " + position.coords.longitude; 
} 
</script> 

Answer 2

你必須創建的LocationManager類的實例。您可以使用getLastKnownLocation方法來查找位置。您必須將Location.GPS_PROVIDER作爲參數傳遞。

LocationManager locationManager = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE); 
Location userLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
Log.d("Latitude", userLocation.getLatitude()); 
Log.d("Longitude", userLocation.getLongitude()); 

Answer 3

給你許可：

<uses-permission android:name="android.permission.INTERNET"></uses-permission> 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 

獲取經度緯度&：

LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
double longitude = location.getLongitude(); 
double latitude = location.getLatitude(); 

保存在txt文件：

public void generateLatLongOnSDCard(String sFileName, String sBody){ 
    try 
    { 
     File rootDirFile = new File(Environment.getExternalStorageDirectory(), "LatLong"); 
     if (!rootDirFile.exists()) { 
      rootDirFile.mkdirs(); 
     } 
     File gpxfile = new File(rootDirFile, sFileName); 
     FileWriter writer = new FileWriter(gpxfile); 
     writer.append(sBody); 
     writer.flush(); 
     writer.close(); 
     Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show(); 
    } 
    catch(IOException e) 
    { 
     e.printStackTrace(); 
    } 
    } 

最後您可以閱讀文本文件。

Answer 4

如果您想要獲得更準確的位置Feed，則應該請求更新，最後一個已知位置對您而言不夠用。 GPS_PROVIDER將僅提供來自gps的位置更新，而不是來自網絡提供商。但是，如果您使用NETWORK_PROVIDER，則可以在室內獲得更準確的位置值。

public class MainActivity extends Activity implements LocationListener{ 

    protected LocationManager locationManager; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this); 
    } 

    @Override 
    public void onLocationChanged(Location location) { 
     txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude()); 
    } 

    @Override 
    public void onProviderDisabled(String provider) { 
     Log.d("Latitude","disable"); 
    } 

    @Override 
    public void onProviderEnabled(String provider) { 
     Log.d("Latitude","enable"); 
    } 

    @Override 
    public void onStatusChanged(String provider, int status, Bundle extras) { 
     Log.d("Latitude","status"); 
    } 
}