{Android App}我如何显示距离当前位置和指定点的距离？

问题描述：

我研究这几个小时，唯一的答案，我看到我指向 http://developer.android.com/reference/android/location/Location.html {Android App}我如何显示距离当前位置和指定点的距离？

和使用方法

公共静态无效distanceBetween（双startLatitude，双startLongitude，双endLatitude，双endLongitude，浮动[]结果）

我需要帮助理解这是如何工作与我的应用程序。这是我如何检索我的位置。

LocationManager locationManager; 
    String context = Context.LOCATION_SERVICE; 
    locationManager = (LocationManager)getSystemService(context); 

    String provider = LocationManager.GPS_PROVIDER; 
    Location location = locationManager.getLastKnownLocation(provider); 

    updateWithNewLocation(location); 
    } 

    private void updateWithNewLocation(Location location) { 
    String latLongString; 
    TextView myLocationText; 
    myLocationText = (TextView)findViewById(R.id.myLocationText); 
    if (location != null) { 
     double lat = location.getLatitude(); 
     double lng = location.getLongitude(); 
     latLongString = "Lat:" + lat + "\nLong:" + lng; 
    } else { 
     latLongString = "No location found"; 
    } 
    myLocationText.setText("Your Current Position is:\n" + 
          latLongString); 
    }

可有人请帮我出一点点了解如何导入我的当前位置到这个方程，然后让我的应用程序显示的距离是多少？谢谢

首先你没有得到*当前位置，使用[requestSingleUpdate（）]（http://developer.android.com/reference/android/location/LocationManager.html）来做到这一点。其次，你正在计算当前位置和....之间的距离？ – Reno 2011-03-04 03:41:38

答

创建一个位置监听器

方法isAccurateForUse是简单地检查位置精度的自定义方法。

这应该工作：

public boolean locChanged = false; 
public LocationManager locMgr = null; 
public Location referenceL = null; // Your reference location 
public Location currentKL = null; // Current known location 
public Location currentLKL = null; // Current last known location 

//Initialise the GPS listener 
locMgr = (LocationManager) appCtx.getSystemService(Context.LOCATION_SERVICE); 
locMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, fixGpsListener); 
currentLKL = locMgr.getLastKnownLocation(LocationManager.GPS_PROVIDER); 

//Define the GPS listener 
LocationListener fixGpsListener = new LocationListener() 
{ 
    public void onLocationChanged(Location location) 
    { 
     locChanged = true; 
     if (currentKL == null) 
      currentKL = location; 
     else if (isAccurateForUse()) 
     { 
      currentLKL = currentKL; 
      currentKL = location; 
      updateDistance(meterToKilometer(currentKL.distanceTo(referenceL))); 
     } 
    } 

    public void onProviderDisabled(String provider) 
    {} 

    public void onProviderEnabled(String provider) 
    {} 

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

currentKL.distanceTo（referenceL）>>给出米

meterToKilometer的距离>>转换米到千平方米

updateDistance >>这种方法需要一个字符串并更新显示距离的文本视图。

干杯

答

public double calcdist() 
      { 
       int MILLION = 1000000; 
       int EARTH_RADIUS_KM = 6371; 

       double lat1 = la1/MILLION;// latitude of location 1 
      double lon1 = lo1/MILLION; //longitude of location 1 
      double lat2 = la2/MILLION; //latitude of location 2 
      double lon2 = lo2/MILLION;//longitude of location 2 

      double lat1Rad = Math.toRadians(lat1); 
      double lat2Rad = Math.toRadians(lat2); 
      double deltaLonRad = Math.toRadians(lon2 - lon1); 

      double dist = Math.acos(Math.sin(lat1Rad) * Math.sin(lat2Rad) + Math.cos(lat1Rad) * Math.cos(lat2Rad) 
        * Math.cos(deltaLonRad)) 
        * EARTH_RADIUS_KM; 
      return dist; 

}

您可以使用此代码，如果你已经有纬度和两个位置的经度。

{Android App}我如何显示距离当前位置和指定点的距离？

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