我开发了一个带有列表视图的mapview，我需要让附近的地方（1公里以内）显示在列表中。
GeoP = lat，来自gps的当前用户坐标的长度。
我该怎么做？
我想我应该得到当前位置，即GeoP和Json应该根据每个位置之间的距离进行排序。如何编码？
public class MappingActivity extends MapActivity {
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in
// Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 10000; // in
// Milliseconds
protected LocationManager locationManager;
Intent intent;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapV = (MapView) findViewById(R.id.mapview);
checkin = (Button) findViewById(R.id.check);
addplace = (Button) findViewById(R.id.addp);
result = (TextView) findViewById(R.id.result);
ListView list = (ListView) findViewById(R.id.list);
intent = getIntent();
Naming = intent.getStringExtra("name1");
result.setText(Naming);
overlaylist = mapV.getOverlays();
d = getResources().getDrawable(R.drawable.point);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, new MyLocationListener());
Location location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
lat = location.getLatitude();
lng = location.getLongitude();
}
Button check = (Button) findViewById(R.id.check);
Button addplace = (Button) findViewById(R.id.addp);
Button nearby = (Button) findViewById(R.id.point);
check.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(
"http://capturehouse.lk/authenticate_user.php");
try {
String Latitude = String.valueOf(lat);
String Longtitude = String.valueOf(lng);
String Name = String.valueOf(Naming);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
2);
nameValuePairs
.add(new BasicNameValuePair("Lati", Latitude));
nameValuePairs.add(new BasicNameValuePair("Longi",
Longtitude));
nameValuePairs.add(new BasicNameValuePair("Name", Name));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
Log.w("SENCIDE", "Execute HTTP Post Request");
HttpResponse response = httpclient.execute(httppost);
String str = inputStreamToString(
response.getEntity().getContent()).toString();
Log.w("SENCIDE", str);
if (str.toString().equalsIgnoreCase("True")) {
Log.w("SENCIDE", "TRUE");
Context context = getApplicationContext();
CharSequence text = "You Are Checked-In";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
} else {
Log.w("SENCIDE", "FALSE");
Context context = getApplicationContext();
CharSequence text = "Please Try Again.";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private Object inputStreamToString(InputStream is) {
// TODO Auto-generated method stub
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(
new InputStreamReader(is));
// Read response until the end
try {
while ((line = rd.readLine()) != null) {
total.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
// Return full string
return total;
}
});
addplace.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
// TextView result = (TextView) findViewById(R.id.result);
result.setText("Added the Plce");
}
});
nearby.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
// TextView result = (TextView) findViewById(R.id.result);
result.setText("Nearby the Plce");
}
});
// json query
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser
.getJSONFromUrl("http://api.androidhive.info/contacts/");
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item, new String[] { TAG_NAME, TAG_EMAIL,
TAG_PHONE_MOBILE }, new int[] { R.id.name, R.id.email,
R.id.mobile });
list.setAdapter(adapter);
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
public class MyLocationListener implements LocationListener {
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
String message = String.format("You are Here");
Toast.makeText(MappingActivity.this, message, Toast.LENGTH_LONG)
.show();
GeoP = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
mControl = mapV.getController();
mControl.animateTo(GeoP);
mControl.setZoom(19);
MapOverlay mapOverlay = new MapOverlay();
List<Overlay> listOfOverlays = mapV.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
mapV.invalidate();
}
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}