我正在使用每个屏幕的片段构建搜索应用。我将搜索工作并将JSON结果存储在主活动中的ArrayList<Map<String, String>>中，以便其他片段可以访问它。当前的问题出在我的resultsFragment上，我在主ListFragment中嵌入了一个Google MapFragment，下面是一个listView。地图已成功填充，但列表为空。我花了好几个小时试图解决这个问题。以下是resultsFragment的代码
package com.wny.wecare.fragment;
import java.util.ArrayList;
import java.util.Map;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.wny.wecare.MainActivity;
import com.wny.wecare.R;
import android.app.ListFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class ResultsFragment extends ListFragment {
ArrayList<Map<String, String>> resultsList = new ArrayList<Map<String, String>>();
private GoogleMap map;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_results, container, false);
//Get search results from stored ArrayList
resultsList = MainActivity.getResultsList();
//Build listView from results
ListView lv =(ListView) getActivity().findViewById(android.R.id.list);
ListAdapter adapter = new SimpleAdapter(getActivity(), resultsList,
R.layout.custom_row_view, new String[] { "AgencyID", "AgencyName",
"Address1" }, new int[] { R.id.text1, R.id.text2,
R.id.text3 });
// updating listview
setListAdapter(adapter);
//Setup embedded Google Map fragment
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
map.setMapType(GoogleMap.MAP_TYPE_HYBRID);
//Add markers to the map from resultsList
for (int i = 0; i < resultsList.size(); i++) {
Double latitude = Double.valueOf(resultsList.get(i).get("Lat"));
Double longitude = Double.valueOf(resultsList.get(i).get("Lng"));
String mname = resultsList.get(i).get("AgencyName");
LatLng posit = new LatLng(latitude, longitude);
map.addMarker(new MarkerOptions()
.position(posit)
.title(mname));
}
return rootView;
}
}
如果这里有用的话是我的homeFragment中的代码（搜索结果存储到ArrayList中）
package com.wny.wecare.fragment;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import com.wny.wecare.MainActivity;
import com.wny.wecare.R;
import com.wny.wecare.handler.JSONParser;
public class HomeFragment extends Fragment implements OnItemSelectedListener, OnClickListener{
private OnFragmentInteractionListener mListener;
private Spinner spinner;
private Button btnSubmit;
private static final String[] list={"Alden", "Amherst", "Angola",
"Blasdell", "Boston", "Bowmansville", "Buffalo", "Cheektowaga", "Clarence",
"Depew", "Derby", "East Aurora", "Eden", "Elma", "Getzville", "Gowanda",
"Grand Island", "Holland", "Irving", "Kenmore", "Lackawanna", "Lake View",
"Lancaster", "Lawtons", "North Collins", "Orchard Park", "Snyder", "Springville",
"Tonawanda", "West Seneca", "Williamsville"};
// Setup ArrayList from main activity to store results
ArrayList<Map<String, String>> resultsList = new ArrayList<Map<String, String>>();
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
// products JSONArray
JSONArray agency = null;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
btnSubmit = (Button) rootView.findViewById(R.id.town_search);
btnSubmit.setOnClickListener(this);
spinner =(Spinner)rootView.findViewById(R.id.spinner);
spinner.setOnItemSelectedListener(this);
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_spinner_item,list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(dataAdapter);
return rootView;
}
// Check if parent activity implements the interface
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener =
(OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
//add items into spinner dynamically
/*public void addItemsOnSpinner2(View v) {
addItemsOnSpinner2(v);
final List<String> list = new ArrayList<String>();
list.add("list 1");
list.add("list 2");
list.add("list 3");
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_spinner_item,list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
}*/
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.town_search:
String town = (String) spinner.getSelectedItem().toString();
agencySearch(town);
mListener.onFragmentButton();
break;
case R.id.zip_search:
String strZip = ((EditText) v.findViewById(R.id.txt_zip)).getText().toString().trim();
int zip = Integer.parseInt(strZip);
agencySearch(zip);
mListener.onFragmentButton();
break;
/*case R.id.btn_location:
String strZip = v.findViewById(R.id.txt_zip).toString();
int zip = Integer.parseInt(strZip);
agencySearch(zip);
mListener.onFragmentButton();
break;*/
}
}
@Override
public void onItemSelected(AdapterView<?> parent,
View v, int position, long id) {
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// TODO Auto-generated method stub
}
public void agencySearch(String tsearch) {
// Setting the URL for the Search by Town
String url_search_agency = "http://www.infinitycodeservices.com/get_agency_by_city.php";
// Building parameters for the search
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("City", tsearch));
// Getting JSON string from URL
JSONArray json = jParser.getJSONFromUrl(url_search_agency, params);
for (int i = 0; i < json.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
try {
JSONObject c = (JSONObject) json.get(i);
//Fill map
Iterator iter = c.keys();
while(iter.hasNext()) {
String currentKey = (String) iter.next();
map.put(currentKey, c.getString(currentKey));
}
resultsList.add(map);
}
catch (JSONException e) {
e.printStackTrace();
}
};
MainActivity.setResultsList(resultsList);
}
public void agencySearch(int zsearch) {
// Setting the URL for the Search by Zip
String url_search_agency = "http://www.infinitycodeservices.com/get_agency_by_zip.php";
// Building parameters for the search
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("zip", Integer.toString(zsearch)));
// Getting JSON string from URL
JSONArray json = jParser.getJSONFromUrl(url_search_agency, params);
for (int i = 0; i < json.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
try {
JSONObject c = (JSONObject) json.get(i);
//Fill map
Iterator iter = c.keys();
while(iter.hasNext()) {
String currentKey = (String) iter.next();
map.put(currentKey, c.getString(currentKey));
}
resultsList.add(map);
}
catch (JSONException e) {
e.printStackTrace();
}
};
MainActivity.setResultsList(resultsList);
}
}