在我的应用程序用户应该标记起始点然后应绘制路径，然后当用户单击按钮时，此路径应显示在新活动中 如何在另一个活动中显示此路径 这是我的代码 抱歉英语不好
package com.example.project;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener;
import com.google.android.gms.maps.GoogleMap.OnMarkerClickListener;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
public class AirportActivity extends Activity implements OnMapClickListener, OnMapLongClickListener, OnMarkerClickListener{
boolean markerClicked;
PolylineOptions rectOptions;
Polyline polyline;
GoogleMap googleMap;
List<LatLng> points;
List<Polyline> polylines;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.airportactivity);
googleMap = ((MapFragment)getFragmentManager().findFragmentById(
R.id.mapView)).getMap();
//googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
// googleMap.animateCamera(CameraUpdateFactory.newLatLng(point));
points = new ArrayList<LatLng>();
polylines = new ArrayList<Polyline>();
String[] placeNames = {"Cairo International Airport","Alexandria International Airport","Borg El Arab Airport",
"Marsa Matrouh Airport","Sharm el-Sheikh International Airport","Taba International Airport","El Kharga Airport",
"Assiut Airport","Luxor International Airport","Aswan International Airport","El Arish International Airport",
"St. Catherine International Airport","Sharq Al-Owainat Airport","Abu Simbel Airport","Sohag International Airport",
"Port Said Airport","El Tor Airport","Dakhla Oasis Airport","Marsa Alam International Airport","Cairo West Air Base","Almaza Air Force Base"};
String[] placeNamesSnippet = {"Cairo International Airport1","Alexandria International Airport2","Borg El Arab Airport3", "Marsa Matrouh Airport4","Sharm el-Sheikh International Airport5","Taba International Airport6","El Kharga Airport7", "Assiut Airport8","Luxor International Airport9","Aswan International Airport10","El Arish International Airport11", "St. Catherine International Airport12","Sharq Al-Owainat Airport13","Abu Simbel Airport14","Sohag International Airport15", "Port Said Airport16","El Tor Airport17","Dakhla Oasis Airport18","Marsa Alam International Airpor19t","Cairo West Air Bas20e","Almaza Air Force Base21"};
Double[] placeLatitude = {30.111370, 31.192553, 30.917138,31.324435,27.978620,29.590988,27.188222,27.047695, 25.670264,
23.960397,31.076449,28.684537,22.580600,22.375813,26.331926,31.281150,28.208842,25.688581,25.558141,
30.116704,30.095975};
Double[] placeLongitude = {31.413910, 29.953141,29.693375, 27.222200,34.393354,34.778946 , 33.800840, 31.013473 , 32.704063,
32.821163,33.832256,34.062882, 28.720754, 31.611667,31.728437,32.242223,33.645257,28.972356,34.582821,
30.916667,31.362748};
for(int i = 0 ; i<21;i++)
{
googleMap.addMarker(new MarkerOptions()
.snippet(placeNamesSnippet[i])
.position(new LatLng(placeLatitude[i], placeLongitude[i]))
.title(placeNames[i]));
points.add(new LatLng(placeLatitude[i], placeLongitude[i]));
markerClicked = false;
}
markerClicked = false;
googleMap.setOnMapLongClickListener(this);
googleMap.setOnMarkerClickListener(this);
}
@Override
public boolean onMarkerClick(Marker marker) {
if(points.size() > 2)
{
FindShortestPath();
}
else if(points.size() == 2)
{ if(markerClicked){
if(polyline != null){
polyline.remove();
polyline = null;
}
rectOptions.add(marker.getPosition());
rectOptions.color(Color.RED);
polyline = googleMap.addPolyline(rectOptions);
}else{
if(polyline != null){
polyline.remove();
polyline = null;
}
rectOptions = new PolylineOptions().add(marker.getPosition());
markerClicked = true;
}
}
return true;
}
public void onClick(View view) {
startActivity(new Intent("net.learn2develop.ListMapActivity"));
}
public static double distance(LatLng StartP, LatLng EndP) {
double lat1 = StartP.latitude;
double lat2 = EndP.latitude;
double lon1 = StartP.longitude;
double lon2 = EndP.longitude;
double dLat = Math.toRadians(lat2-lat1);
double dLon = Math.toRadians(lon2-lon1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
Math.sin(dLon/2) * Math.sin(dLon/2);
double c = 2 * Math.asin(Math.sqrt(a));
return 6366000 * c;
}
// calculate distances matrix then get shortest path then call draw
public void FindShortestPath()
{
TSPNearestNeighbour tsp = new TSPNearestNeighbour();
int adjacencyMatrix[][] = new int[points.size()][];
int counter = 0,innerCounter ;
int[] result = new int[points.size()];
for(LatLng point : points)
{
innerCounter=0;
adjacencyMatrix[counter] = new int[points.size()];
for(LatLng point1 : points)
{
if(point.equals(point1))
{
adjacencyMatrix[counter][innerCounter] = 0;
}
else
adjacencyMatrix[counter][innerCounter] =(int) distance(point,point1);
innerCounter ++;
}
counter ++;
}
result = tsp.tsp(adjacencyMatrix);
DrawShortestPath(result);
}
//draws the shortest path with markers
public void DrawShortestPath(int[] path)
{
googleMap.clear();
int numOfNodes = points.size();
for(LatLng point : points)
{
googleMap.addMarker(new MarkerOptions().icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE))
.position(point));
}
for (int index = 0 ; index < numOfNodes-1 ; index++)
{
googleMap.addPolyline(new PolylineOptions()
.add(points.get(path[index]), points.get(path[index+1]))
.width(3)
.color(Color.RED));
}
}
class TSPNearestNeighbour
{
private int numberOfNodes;
private Stack<Integer> stack;
public TSPNearestNeighbour()
{
stack = new Stack<Integer>();
}
public int[] tsp(int adjacencyMatrix[][])
{
numberOfNodes = adjacencyMatrix[0].length ;
int[] result = new int[adjacencyMatrix[0].length];
int resultCounter = 1;
int[] visited = new int[numberOfNodes];
visited[0] = 1;
stack.push(0);
int element, dst = 0, i;
int min = Integer.MAX_VALUE;
boolean minFlag = false;
result[0] = 0;
//System.out.print(1 + "\t");
while (!stack.isEmpty())
{
element = stack.peek();
i = 0;
min = Integer.MAX_VALUE;
while (i < numberOfNodes)
{
if (adjacencyMatrix[element][i] > 1 && visited[i] == 0)
{
if (min > adjacencyMatrix[element][i])
{
min = adjacencyMatrix[element][i];
dst = i;
minFlag = true;
}
}
i++;
}
if (minFlag)
{
visited[dst] = 1;
stack.push(dst);
result[resultCounter] = dst;
resultCounter++;
//System.out.print(dst + "\t");
minFlag = false;
continue;
}
stack.pop();
}
return result;
}
}
@Override
public void onMapClick(LatLng arg0) {
// TODO Auto-generated method stub
}
@Override
public void onMapLongClick(LatLng arg0) {
// TODO Auto-generated method stub
}
答案 0 :(得分：0)
如果您已将信息作为数组，则可以将其作为额外内容传递给您用于启动新活动的Intent。
像这样修改你的点击：
public void onClick(View view) {
Intent i = new Intent("net.learn2develop.ListMapActivity");
i.putExtra("latitudes", placeLatitude);
i.putExtra("longitudes", placeLongitude);
//call putExtra(key, value) for each array you want to pass to the other activity
startActivity(i);
}
您可以阅读有关在活动here或official documentation之间传递值的详情。