Android：如何知道地圖中的活動多段線API V2

Question

我有應用程序在android地圖中製作多段線。我用onMapLongClickListener檢查動態多段線。我檢查存儲折線路徑的ArrayList。問題是，當我有兩條分開的多段線並且我想檢查最近的路徑時，我只能用最後一條多段線檢查它，我想檢查第一條多段線，但它不起作用。我的代碼有什麼問題？

package com.evy; 
 

 
import java.util.ArrayList; 
 

 
import com.google.android.gms.maps.GoogleMap; 
 
import com.google.android.gms.maps.SupportMapFragment; 
 
import com.google.android.gms.maps.GoogleMap.OnMapClickListener; 
 
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener; 
 
import com.google.android.gms.maps.model.LatLng; 
 
import com.google.android.gms.maps.model.MarkerOptions; 
 
import com.google.android.gms.maps.model.PolylineOptions; 
 

 
import android.support.v4.app.FragmentActivity; 
 
import android.graphics.Color; 
 
import android.location.Location; 
 
import android.os.Bundle; 
 
import android.view.Menu; 
 
import android.view.MenuItem; 
 
import android.view.View; 
 
import android.view.View.OnClickListener; 
 
import android.widget.Button; 
 
import android.widget.Toast; 
 

 
public class MainActivity extends FragmentActivity { 
 
\t GoogleMap map; 
 
\t private boolean isNewPoly=false; 
 
\t ArrayList<LatLng> points; 
 
\t PolylineOptions polylineOptions; 
 
\t String list; 
 
\t MarkerOptions markerOptions; 
 

 
\t @Override 
 
\t protected void onCreate(Bundle savedInstanceState) { 
 
\t \t super.onCreate(savedInstanceState); 
 
\t \t setContentView(R.layout.activity_main); 
 
\t \t 
 
\t \t SupportMapFragment mapFragment=(SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); 
 
\t \t map=mapFragment.getMap(); 
 
\t \t 
 
\t \t Button stop = (Button) findViewById(R.id.stop); 
 
\t \t Button start = (Button) findViewById(R.id.start); 
 
\t \t 
 
\t \t map.setOnMapClickListener(new OnMapClickListener(){ 
 

 
\t \t \t @Override 
 
\t \t \t public void onMapClick(LatLng point) { 
 
\t \t \t \t // TODO Auto-generated method stub 
 
\t \t \t \t if(isNewPoly){ 
 
\t \t \t \t \t markerOptions = new MarkerOptions().position(point).title("Position").snippet("Latitude: "+point.latitude+" , "+"Longitude: "+point.longitude); 
 
\t \t \t \t \t map.addMarker(markerOptions); 
 
\t \t \t \t \t points.add(point); 
 
\t \t \t \t \t polylineOptions = new PolylineOptions(); 
 
\t \t \t \t \t polylineOptions.color(Color.BLUE); 
 
\t \t \t \t \t polylineOptions.width(3); 
 
\t \t \t \t \t polylineOptions.addAll(points); 
 
\t \t \t \t \t map.addPolyline(polylineOptions); 
 
\t \t \t \t } 
 
\t \t \t \t else { 
 
\t \t \t \t \t 
 
\t \t \t \t \t cek(point); 
 
\t \t \t \t \t 
 
\t \t \t \t } 
 
\t \t \t } 
 
\t \t }); 
 
\t \t 
 
\t \t map.setOnMapLongClickListener(new OnMapLongClickListener(){ 
 

 
\t \t \t @Override 
 
\t \t \t public void onMapLongClick(LatLng poin) { 
 
\t \t \t \t // TODO Auto-generated method stub 
 
\t \t \t \t //if(isNewPoly){ 
 
\t \t \t \t \t cek(poin); 
 
\t \t \t \t //} 
 
\t \t \t } 
 
\t \t \t 
 
\t \t }); 
 
\t \t 
 
\t \t start.setOnClickListener(new OnClickListener(){ 
 

 
\t \t \t @Override 
 
\t \t \t public void onClick(View arg0) { 
 
\t \t \t \t // TODO Auto-generated method stub 
 
\t \t \t \t points=new ArrayList<LatLng>(); 
 
\t \t \t \t isNewPoly=true; 
 
\t \t \t } 
 
\t \t }); 
 
\t \t 
 
\t \t stop.setOnClickListener(new OnClickListener(){ 
 

 
\t \t \t @Override 
 
\t \t \t public void onClick(View arg0) { 
 
\t \t \t \t // TODO Auto-generated method stub 
 
\t    isNewPoly = false; 
 
\t \t \t } 
 
\t \t }); 
 
\t } 
 
\t 
 
\t public void cek(LatLng poin){ 
 
\t \t float mindist = 0; 
 
\t \t int pos=0; 
 
\t \t Double lat1=poin.latitude; 
 
\t \t Double lng1=poin.longitude; 
 
\t \t 
 
\t \t for(int i=0; i<points.size();i++){ 
 
\t \t \t Double lat=points.get(i).latitude; 
 
\t \t \t Double lng=points.get(i).longitude; 
 
\t \t \t float[] distance = new float [1]; 
 
\t \t \t Location.distanceBetween(lat1, lng1, lat, lng, distance); 
 
\t \t \t if(i==0){ 
 
\t \t \t \t mindist=distance[0]; 
 
\t \t \t } 
 
\t \t \t else if(mindist>distance[0]){ 
 
\t \t \t \t mindist=distance[0]; 
 
\t \t \t \t pos=i; 
 
\t \t \t } 
 
\t \t } 
 
\t \t LatLng ne = points.get(pos); 
 
\t \t Toast.makeText(MainActivity.this, "marker terdekat "+ne+" "+mindist, Toast.LENGTH_LONG).show(); 
 
\t \t MarkerOptions markerOptions = new MarkerOptions().position(poin).title("Position").snippet("Latitude: "+lat1+" , "+"Longitude: "+lng1); 
 
\t \t map.addMarker(markerOptions); 
 
\t \t points=new ArrayList<LatLng>(); 
 
\t \t points.add(ne); 
 
\t \t 
 
\t \t points.add(poin); 
 
\t \t polylineOptions = new PolylineOptions(); 
 
\t \t polylineOptions.color(Color.BLUE); 
 
\t \t polylineOptions.width(3); 
 
\t \t polylineOptions.addAll(points); 
 
\t \t map.addPolyline(polylineOptions); 
 
\t \t 
 
\t } 
 
\t 
 
\t @Override 
 
\t public boolean onCreateOptionsMenu(Menu menu) { 
 

 
\t \t // Inflate the menu; this adds items to the action bar if it is present. 
 
\t \t getMenuInflater().inflate(R.menu.main, menu); 
 
\t \t return true; 
 
\t } 
 

 
\t @Override 
 
\t public boolean onOptionsItemSelected(MenuItem item) { 
 
\t \t // Handle action bar item clicks here. The action bar will 
 
\t \t // automatically handle clicks on the Home/Up button, so long 
 
\t \t // as you specify a parent activity in AndroidManifest.xml. 
 
\t \t int id = item.getItemId(); 
 
\t \t if (id == R.id.action_settings) { 
 
\t \t \t return true; 
 
\t \t } 
 
\t \t return super.onOptionsItemSelected(item); 
 
\t } 
 
}

，這是我做的代碼。謝謝

Answer 1

如果我理解正確，您需要一種方法來跟蹤輸入到地圖中的不同折線。 map.addPolyline(polylineOptions)將返回一個Polyline對象。您可以將這些折線存儲在一個數組中以供以後比較。可以在每個Polyline對象上調用getPoints()以獲取LatLng點。