我正在开发洗衣应用程序。我有这样的listview
(Fragment
),因此用户可以选择项目。
我的问题是当我点击继续然后我再次回到此屏幕时它的值变为零。如何保存listview状态。
我在片段中尝试了这段代码,但没有运气。并且还尝试保存和恢复实例状态方法但面临同样的问题。
// Save the ListView state (= includes scroll position) as a Parceble
Parcelable state = listView.onSaveInstanceState();
// e.g. set new items
listView.setAdapter(adapter);
// Restore previous state (including selected item index and scroll position)
listView.onRestoreInstanceState(state);
ManFragment.java
package info.tranetech.laundry.activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import info.tranetech.laundry.R;
import info.tranetech.laundry.adapter.JSONParser;
public class ManFragment extends Fragment {
private View rootView;
//Dry
public static String TAG_ITEM_MAN = "name";
public static String TAG_PRICE_DRY = "drycleaning_price";
public static String TAG_PRICE_WASH_IRON = "washiron_price";
public static String TAG_PRICE_WASH = "wash_price";
public static String TAG_PRICE_IRON = "iron_price";
public static String Name, Price_Dry, price_wash_iron, price_wash, price_iron;
public static String url_dry = "http://openspace.tranetech.com/mis/Laundry/men_dry.php";
static TextView ItemName, ItemPrice;
public static int Cat_Position;
ArrayList<HashMap<String, String>> DryList = new ArrayList<HashMap<String, String>>();
ArrayList<HashMap<String, String>> WashList = new ArrayList<HashMap<String, String>>();
ArrayList<HashMap<String, String>> WashIronList = new ArrayList<HashMap<String, String>>();
ArrayList<HashMap<String, String>> IronList = new ArrayList<HashMap<String, String>>();
ListView list;
ProgressDialog pdialog;
static Spinner Spin_Man;
public ManFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
rootView = inflater.inflate(R.layout.man_pricelist, container, false);
// Locate the listview in listview_main.xml
list = (ListView) rootView.findViewById(R.id.man_listView);
Spin_Man = (Spinner) rootView.findViewById(R.id.spinner_man);
new DryData().execute();
Spin_Man.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
try {
switch (position) {
case 0:
Cat_Position = position;
Filllist();
getView();
break;
case 1:
Cat_Position = position;
Filllist();
getView();
break;
case 2:
Cat_Position = position;
Filllist();
getView();
break;
case 3:
Cat_Position = position;
Filllist();
getView();
break;
}
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getActivity(), "Position " + position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parentView) {
// your code here
}
});
return rootView;
}
private class DryData extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
pdialog = new ProgressDialog(getActivity());
pdialog.setMessage("Please Wait...");
pdialog.setCancelable(true);
pdialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// TODO Auto-generated method stub
JSONParser jp = new JSONParser();
String jsonStr = jp.makeServiceCall(url_dry, JSONParser.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jobj = new JSONObject(jsonStr);
JSONArray jarray = jobj.getJSONArray("Data");
for (int i = 0; i < jarray.length(); i++) {
JSONObject jobjin = jarray.getJSONObject(i);
String name = jobjin.getString(TAG_ITEM_MAN);
String price_dry = jobjin.getString(TAG_PRICE_DRY);
String price_wash_iron = jobjin.getString(TAG_PRICE_WASH_IRON);
String price_wash = jobjin.getString(TAG_PRICE_WASH);
String price_iron = jobjin.getString(TAG_PRICE_IRON);
HashMap<String, String> add_dry = new HashMap<String, String>();
add_dry.put(TAG_ITEM_MAN, name);
add_dry.put(TAG_PRICE_DRY, price_dry);
HashMap<String, String> add_wash_iron = new HashMap<String, String>();
add_wash_iron.put(TAG_ITEM_MAN, name);
add_wash_iron.put(TAG_PRICE_WASH_IRON, price_wash_iron);
HashMap<String, String> add_wash = new HashMap<String, String>();
add_wash_iron.put(TAG_ITEM_MAN, name);
add_wash.put(TAG_PRICE_WASH, price_wash);
HashMap<String, String> add_iron = new HashMap<String, String>();
add_iron.put(TAG_ITEM_MAN, name);
add_iron.put(TAG_PRICE_IRON, price_iron);
DryList.add(add_dry);
WashList.add(add_wash);
WashIronList.add(add_wash_iron);
IronList.add(add_iron);
}
} catch (JSONException e) {
e.printStackTrace();
// TODO: handle exception
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url_dry");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if (pdialog.isShowing()) {
pdialog.dismiss();
}
Filllist();
}
}
public void Filllist() {
// TODO Auto-generated method stub
Cus adapter = new Cus();
list.setAdapter(adapter);
// Helper.getListViewSize(list);
}
private class Cus extends BaseAdapter {
@Override
public int getCount() {
// TODO Auto-generated method stub
return DryList.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
LayoutInflater inflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
convertView = inflater.inflate(R.layout.price_row, null);
}
ItemName = (TextView) convertView.findViewById(R.id.item_name);
ItemPrice = (TextView) convertView.findViewById(R.id.price);
Name = DryList.get(position).get(TAG_ITEM_MAN).toString();
Price_Dry = DryList.get(position).get(TAG_PRICE_DRY).toString();
price_wash_iron = WashIronList.get(position).get(TAG_PRICE_WASH_IRON).toString();
price_wash = WashList.get(position).get(TAG_PRICE_WASH).toString();
price_iron = IronList.get(position).get(TAG_PRICE_IRON).toString();
if (Cat_Position == 0) {
//set item name
ItemName.setText("" + Name);
ItemPrice.setText("Rs." + Price_Dry);
} else if (Cat_Position == 1) {
//set item name
ItemName.setText("" + Name);
ItemPrice.setText("Rs." + price_iron);
} else if (Cat_Position == 2) {
//set item name
ItemName.setText("" + Name);
ItemPrice.setText("Rs." + price_wash);
} else if (Cat_Position == 3) {
//set item name
ItemName.setText("" + Name);
ItemPrice.setText("Rs." + price_wash_iron);
}
return convertView;
}
}
}
答案 0 :(得分:1)
全局定义Arraylist并将webservices称为:
data