안드로이드 (이동 중에)에서 이동 거리를 계산

Question

안녕하세요 나는 자전거가 움직이는 동안 안드로이드에서 GPS를 사용하여 거리를 계산해야합니다. 나는 aprx 올바른 값을주고 에뮬레이터에서 위도와 경도 값을주고 있어요 그러나 장치의 패킷 데이터를 사용하고 앱을 실행하면 값이 움직임없이 바뀝니다. 이 코드입니다, 제발 제안하십시오.

@Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     //locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     showCurrentLocation(); 
     b2=(Button)findViewById(R.id.button2); 
     b2.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       clearButton(); 
      } 
    });  
    } 

    @SuppressWarnings("unused") 
    protected void showCurrentLocation() { 
     // Getting LocationManager object 
     locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     // Creating an empty criteria object 
     Criteria criteria = new Criteria(); 
     // Getting the name of the provider that meets the criteria 
     provider = locationManager.getBestProvider(criteria, false); 

     if (provider != null && !provider.equals("")) { 
      Location location = locationManager.getLastKnownLocation(provider); 

      locationManager.requestLocationUpdates(provider, 20000, 1, this); 
      clat = location.getLatitude(); 
      clon = location.getLongitude(); 
      a[0] = clat; 
      a[1] = clon; 

      if (location != null) 
       onLocationChanged(location); 
      else 
       Toast.makeText(getBaseContext(), "Location can't be retrieved", 
         Toast.LENGTH_SHORT).show(); 

     } else { 
      Toast.makeText(getBaseContext(), "No Provider Found", 
        Toast.LENGTH_SHORT).show(); 
     } 
    } 

    @Override 
    public void onLocationChanged(Location location) { 
     // Getting reference to TextView tv_longitude 
     locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     // Creating an empty criteria object 
     Criteria criteria = new Criteria(); 
     // Getting the name of the provider that meets the criteria 
     provider = locationManager.getBestProvider(criteria, false); 

     if (provider != null && !provider.equals("")) { 
      // Get the location from the given provider 
      Location location1 = locationManager.getLastKnownLocation(provider); 
      locationManager.requestLocationUpdates(provider, 20000, 1, this); 
      plat = location.getLatitude(); 
      plon = location.getLongitude(); 
      a[2] = plat; 
      a[3] = plon; 
      if(a[0]!=a[2]||a[1]!=a[3]) 
     { 
       dis += getDistance(a); 
     } 

      a[0] = plat; 
      a[1] = plon; 
      Log.e("aa", String.valueOf(dis)); 
      TextView tvDistance = (TextView) findViewById(R.id.textView1); 
      tvDistance.setText(String.valueOf(dis) + " km"); 
     } 
    } 
    public double getDistance(double a[]) { 
    double earthRadius = 6371; //kilometers 
    double dLat = Math.toRadians(a[2] -a[0]); 
    double dLng = Math.toRadians(a[3] -a[1]); 
    double b = Math.sin(dLat/2) * Math.sin(dLat/2) + 
       Math.cos(Math.toRadians(a[0])) * Math.cos(Math.toRadians(a[2])) * 
       Math.sin(dLng/2) * Math.sin(dLng/2); 
    double c = 2 * Math.atan2(Math.sqrt(b), Math.sqrt(1-b)); 
    float dist = (float) (earthRadius * c); 

    return dist; 
    } 

    protected void clearButton(){ 
     dis=0; 
     showCurrentLocation(); 
    } 

Answer 1

당신은 단계를하고 위치가 다릅니다하지 않을 경우 getDistance를 호출하지만, 경과 시간은 자전거 속도와 관련이 때 수 (1 초?).

private long timestamp = 0; 

public double getDistance(double a[]) { 
    timestamp = System.currentTimeMillis(); 
    (....) 
} 


public void onLocationChanged(Location location) { 
    (...) 
    if(System.currentTimeMillis() - timestamp > 1000){ 
      dis += getDistance(a); 
    }