我可以从我的数据库中检索标记（Lat＆amp; Lng），但我不会将检索到的标记存储为数组，然后在adroid的另一个活动中使用它
package com.map.driver;
import android.os.AsyncTask;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
public class DriRetMap extends FragmentActivity {
private GoogleMap mMap; // Might be null if Google Play services APK is not available.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dri_ret_map);
setUpMapIfNeeded();
mMap.setMyLocationEnabled(true);
// Starting locations retrieve task
new RetrieveTask().execute();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
/**
* Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
* installed) and the map has not already been instantiated.. This will ensure that we only ever
* call {@link #setUpMap()} once when {@link #mMap} is not null.
* <p/>
* If it isn't installed {@link SupportMapFragment} (and
* {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
* install/update the Google Play services APK on their device.
* <p/>
* A user can return to this FragmentActivity after following the prompt and correctly
* installing/updating/enabling the Google Play services. Since the FragmentActivity may not
* have been completely destroyed during this process (it is likely that it would only be
* stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
* method in {@link #onResume()} to guarantee that it will be called.
*/
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
setUpMap();
}
}
}
// Adding marker on the GoogleMaps
private void addMarker(LatLng latlng) {
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latlng);
markerOptions.title(latlng.latitude + "," + latlng.longitude);
mMap.addMarker(markerOptions);
}
private class RetrieveTask extends AsyncTask<Void, Void, String> {
@Override
protected String doInBackground(Void... params) {
String strUrl = "http://192.168.43.77/location_marker_mysql/retrieve.php";
URL url = null;
StringBuffer sb = new StringBuffer();
try {
url = new URL(strUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream iStream = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(iStream));
String line = "";
while( (line = reader.readLine()) != null){
sb.append(line);
}
reader.close();
iStream.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
new ParserTask().execute(result);
}
}
// Background thread to parse the JSON data retrieved from MySQL server
private class ParserTask extends AsyncTask<String, Void, List<HashMap<String, String>>>{
@Override
protected List<HashMap<String,String>> doInBackground(String... params) {
MarkerJSONParser markerParser = new MarkerJSONParser();
JSONObject json = null;
try {
json = new JSONObject(params[0]);
} catch (JSONException e) {
e.printStackTrace();
}
List<HashMap<String, String>> markersList = markerParser.parse(json);
return markersList;
}
@Override
protected void onPostExecute(List<HashMap<String, String>> result) {
for(int i=0; i<result.size();i++){
HashMap<String, String> marker = result.get(i);
LatLng latlng = new LatLng(Double.parseDouble(marker.get("lat")), Double.parseDouble(marker.get("lng")));
addMarker(latlng);
}
}
}
/**
* This is where we can add markers or lines, add listeners or move the camera. In this case, we
* just add a marker near Africa.
* <p/>
* This should only be called once and when we are sure that {@link #mMap} is not null.
*/
private void setUpMap() {
mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
}
}
答案 0 :(得分：0)
如果你想将你的lat和long传递给另一个活动，请使用下面的包，
在活动A中，
Intent mIntent = new Intent(this, ActivityB.class);
Bundle extras = mIntent.getExtras();
extras.putString("lat", latitudevalue);
extras.putString("long", longitudevalue);
在活动B中，
String lat= getIntent().getExtras().getString("lat");
String long= getIntent().getExtras().getString("long");
答案 1 :(得分：0)
为什么不在第二个活动中再次检索它们或将其存储在＆＃34;缓存＆＃34;目录或数据库？如果他们是少数也许不值得，但如果他们是数千，那么避免太大的可分解的东西可能是好的。
在任何情况下，当您将标记添加到地图时，您可以将它们保存到本地列表（您将列表设置并初始化为本地变量）
List<LatLng> markerPositions = new ArrayList<LatLng>
// Adding marker on the GoogleMaps
private void addMarker(LatLng latlng) {
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latlng);
markerOptions.title(latlng.latitude + "," + latlng.longitude);
mMap.addMarker(markerOptions);
markerPositions.add(latlng);
}
你不能传递Marker对象，因为它不是可分辨的，而LatLng是。 然后将列表添加到intent中： http://developer.android.com/reference/android/content/Intent.html#putParcelableArrayListExtra(java.lang.String，java.util.ArrayList）
做的：
intent.putParcelableArrayListExtra("points",markerPositions);
List<LatLng> positions = intent.getParcelableArrayListExtra("points");
然后，您再次向地图添加新标记或对位置执行任何操作。 标记不能直接传递，因为它们与父图很紧密。