从字符串数组创建Android位置
从字符串数组创建Android位置
提问于 2013-10-09 21:18:37
我正在开发一个Android应用程序。我需要比较一下地点，看看它们之间的距离。不过，我有很多。我发现的最简单的方法是将它们存储在字符串数组中，然后比较它们。我已经搜索过了，但是我还没有找到一种方法将一个项从字符串数组生成到一个位置。我试过：
double distance
Location locationA = new Location(“point A”)
locationA.setLatitude(latitude);
locationA.setLongitude(Longitude);
Location locationB = new Location(“point B”);
locationB.setLatitude(Latitude.get(0));
LocationB.setLongitude(latitude.get(0));
distance = locationA.distanceTo(locationB);但不起作用。我的代码张贴在下面：
NearestStations.java
public class Neareststations extends Activity implements LocationListener {
LocationManager mLocationManager;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.neareststations);
// Show the Up button in the action bar.
getActionBar().setDisplayHomeAsUpEnabled(true);
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Location location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();
Log.i("MYTAG", String.valueOf(longitude));
Log.i("MYTAG", String.valueOf(latitude));
if(location != null && location.getTime() > Calendar.getInstance().getTimeInMillis() - 2 * 60 * 1000) {
// Do something with the recent location if it is less than two minutes old
Log.i("MYTAG", String.valueOf(location));
Log.i("MYTAG", String.valueOf(longitude));
Log.i("MYTAG", String.valueOf(latitude));
}
else {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5, 50, this);
Log.i("MYTAG", String.valueOf(location));
}
}
public void onLocationChanged(Location location) {
if (location != null) {
// Do something withthe current location
Log.i("MYTAG", String.valueOf(location));
}
}
public void onProviderDisabled(String arg0) {}
public void onProviderEnabled(String arg0) {}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}
String[] Stations = getResources().getStringArray(R.array.Stations);
String[] Longitude = getResources().getStringArray(R.array.Longitude);
String[] Latitude = getResources().getStringArray(R.array.Latitude);
Map<String, String> myMap = new HashMap<String, String>();{
for (int i = 0; i <8; i++) {
myMap.put(Stations[i], Latitude[i]);
}
}
Map<String, String> myMap1 = new HashMap<String, String>();{
for (int h = 0; h <8; h++) {
myMap1.put(Stations[h], Longitude[h]);
}
}我该怎么做？我的字符串数组是标准的，有一些条目，如
<item>-87.669147</item>
<item>-87.680622</item>谢谢你的帮助。
回答 2
Stack Overflow用户
回答已采纳
发布于 2013-10-09 21:49:37
字符串需要转换成双倍。另外，在比较两个点时，您应该使用distanceBetween()，但是distanceTo()在较小的距离上工作得很好。
下面是一个将字符串值转换为双倍以便与位置一起使用的基本示例。距离将以米为单位返回，所以如果你想要的话，乘以0.000621371192237334。
double distance;
String str_lat_start = "29.287260";
String str_lon_start = "-81.100327";
String str_lat_end = "26.016045";
String str_lon_end = "-80.150169";
double lat_start = 0;
double lon_start = 0;
double lat_end = 0;
double lon_end = 0;
try {
lat_start = Double.parseDouble( str_lat_start );
lon_start = Double.parseDouble( str_lon_start );
lat_end = Double.parseDouble( str_lat_end );
lon_end = Double.parseDouble( str_lon_end );
} catch (NumberFormatException e) {
Log.v("Main", "Convert to Double Failed : ");
}
Location locationA = new Location("point A");
locationA.setLatitude( lat_start );
locationA.setLongitude( lon_start );
Location locationB = new Location("point B");
locationB.setLatitude( lat_end );
locationB.setLongitude( lon_end );
distance = locationA.distanceTo(locationB) * 0.000621371192237334; Stack Overflow用户
发布于 2013-10-09 22:00:32
float[] results = new float[3];
Location.distanceBetween(locationA.getLatitude(), locationA.getLongitude(), locationB.getLatitude(), locationB.getLongitude(), results);A和B之间的距离是results[0]。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/19282948
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