动态列表视图保存状态 [英] Dynamic listview save state
本文介绍了动态列表视图保存状态的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在洗衣服的应用程序。我有一个列表视图
(片段
),这样使用户可以选择的项目。
我的问题是,当我点击继续,然后我回到这个画面再次它的价值为零。我如何保存列表视图状态。
我想这code在我的片段,但没有运气。而且也尽量保存和恢复实例状态的方法,但面临着同样的问题。
//保存的ListView状态(=包括滚动位置)作为Parceble
Parcelable状态= listView.onSaveInstanceState();//例如设置新项目
listView.setAdapter(适配器);//恢复previous状态(包括所选项目的索引和滚动位置)
listView.onRestoreInstanceState(州);
ManFragment.java
包info.tranetech.laundry.activity;进口android.app.ProgressDialog;
进口android.content.Context;
进口android.os.AsyncTask;
进口android.os.Bundle;
进口android.support.v4.app.Fragment;
进口android.util.Log;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.AdapterView;
进口android.widget.AdapterView.OnItemSelectedListener;
进口android.widget.BaseAdapter;
进口android.widget.ListView;
进口android.widget.Spinner;
进口android.widget.TextView;
进口android.widget.Toast;进口org.json.JSONArray;
进口org.json.JSONException;
进口org.json.JSONObject;进口的java.util.ArrayList;
进口的java.util.HashMap;进口info.tranetech.laundry.R;
进口info.tranetech.laundry.adapter.JSONParser;
公共类ManFragment扩展片段{ 私人查看rootView;
//干
公共静态字符串TAG_ITEM_MAN =名;
公共静态字符串TAG_PRICE_DRY =drycleaning_price;
公共静态字符串TAG_PRICE_WASH_IRON =washiron_price;
公共静态字符串TAG_PRICE_WASH =wash_price;
公共静态字符串TAG_PRICE_IRON =iron_price;
公共静态字符串名称,Price_Dry,price_wash_iron,price_wash,price_iron;
公共静态字符串url_dry =http://openspace.tranetech.com/mis/Laundry/men_dry.php;
静态的TextView ITEMNAME,ITEMPRICE;
公共静态INT Cat_Position;
ArrayList的<&HashMap的LT;字符串,字符串>> DryList =新的ArrayList<&HashMap的LT;字符串,字符串>>();
ArrayList的<&HashMap的LT;字符串,字符串>> WashList =新的ArrayList<&HashMap的LT;字符串,字符串>>();
ArrayList的<&HashMap的LT;字符串,字符串>> WashIronList =新的ArrayList<&HashMap的LT;字符串,字符串>>();
ArrayList的<&HashMap的LT;字符串,字符串>> IronList =新的ArrayList<&HashMap的LT;字符串,字符串>>();
ListView控件列表;
ProgressDialog pdialog; 静态微调Spin_Man; 公共ManFragment(){
//必需的空公共构造
} @覆盖
公共无效的onCreate(捆绑savedInstanceState){
super.onCreate(savedInstanceState);
} @覆盖
公共查看onCreateView(LayoutInflater充气器,容器的ViewGroup,
捆绑savedInstanceState){
//充气的布局该片段
rootView = inflater.inflate(R.layout.man_pricelist,集装箱,FALSE);
//定位listview_main.xml列表视图
名单=(ListView控件)rootView.findViewById(R.id.man_listView);
Spin_Man =(微调)rootView.findViewById(R.id.spinner_man); 新DryData()执行(); Spin_Man.setOnItemSelectedListener(新OnItemSelectedListener(){
@覆盖
公共无效onItemSelected(适配器视图<> parentView,查看selectedItemView,INT位置,长的id){ 尝试{
开关(位置){
情况下0: Cat_Position =位置;
Filllist();
getView(); 打破;
情况1: Cat_Position =位置;
Filllist();
getView(); 打破;
案例2: Cat_Position =位置;
Filllist();
getView(); 打破;
案例3: Cat_Position =位置;
Filllist();
getView(); 打破;
}
}赶上(例外五){
e.printStackTrace();
} Toast.makeText(getActivity(),位置+位置,Toast.LENGTH_SHORT).show();
} @覆盖
公共无效onNothingSelected(适配器视图<> parentView){
//你的code在这里
} }); 返回rootView;
}
私有类DryData扩展的AsyncTask<太虚,太虚,太虚> {
@覆盖
在preExecute保护无效(){
// TODO自动生成方法存根
super.on preExecute();
pdialog =新ProgressDialog(getActivity());
pdialog.setMessage(请稍候...);
pdialog.setCancelable(真);
pdialog.show();
} @覆盖
保护无效doInBackground(虚空......为arg0){
// TODO自动生成方法存根
JSONParser JP =新JSONParser();
字符串jsonStr = jp.makeServiceCall(url_dry,JSONParser.GET);
Log.d(回应:,>中+ jsonStr);
如果(jsonStr!= NULL){
尝试{
JSONObject的jobj =新的JSONObject(jsonStr);
JSONArray jarray = jobj.getJSONArray(数据); 的for(int i = 0; I< jarray.length();我++){
JSONObject的jobjin = jarray.getJSONObject(I) 字符串名称= jobjin.getString(TAG_ITEM_MAN);
字符串price_dry = jobjin.getString(TAG_PRICE_DRY);
字符串price_wash_iron = jobjin.getString(TAG_PRICE_WASH_IRON);
字符串price_wash = jobjin.getString(TAG_PRICE_WASH);
字符串price_iron = jobjin.getString(TAG_PRICE_IRON); HashMap的<字符串,字符串> add_dry =新的HashMap<字符串,字符串>();
add_dry.put(TAG_ITEM_MAN,名);
add_dry.put(TAG_PRICE_DRY,price_dry);
HashMap的<字符串,字符串> add_wash_iron =新的HashMap<字符串,字符串>();
add_wash_iron.put(TAG_ITEM_MAN,名);
add_wash_iron.put(TAG_PRICE_WASH_IRON,price_wash_iron);
HashMap的<字符串,字符串> add_wash =新的HashMap<字符串,字符串>();
add_wash_iron.put(TAG_ITEM_MAN,名);
add_wash.put(TAG_PRICE_WASH,price_wash);
HashMap的<字符串,字符串> add_iron =新的HashMap<字符串,字符串>();
add_iron.put(TAG_ITEM_MAN,名);
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);
}
}赶上(JSONException E){
e.printStackTrace();
// TODO:处理异常
}
}其他{
Log.e(的ServiceHandler,无法从url_dry得到任何数据); }
返回null;
} @覆盖
保护无效onPostExecute(虚空结果){
// TODO自动生成方法存根
super.onPostExecute(结果);
如果(pdialog.isShowing()){
pdialog.dismiss();
} Filllist();
} } 公共无效Filllist(){
// TODO自动生成方法存根
因为不敢适配器=新CUS();
list.setAdapter(适配器);
// Helper.getListViewSize(名单);
} 私有类因为不敢延伸BaseAdapter { @覆盖
公众诠释的getCount(){
// TODO自动生成方法存根
返回DryList.size();
} @覆盖
公共对象的getItem(INT位置){
// TODO自动生成方法存根
返回的位置;
} @覆盖
众长getItemId(INT位置){
// TODO自动生成方法存根
返回的位置;
} @覆盖
公共查看getView(INT位置,查看convertView,父母的ViewGroup){
// TODO自动生成方法存根
LayoutInflater吹气=(LayoutInflater)getActivity()getSystemService(Context.LAYOUT_INFLATER_SERVICE)。
如果(convertView == NULL){
convertView = inflater.inflate(R.layout.price_row,NULL);
}
ITEMNAME =(TextView中)convertView.findViewById(R.id.item_name);
ITEMPRICE =(TextView中)convertView.findViewById(R.id.price); NAME = DryList.get(位置)获得(TAG_ITEM_MAN)的ToString();
Price_Dry = DryList.get(位置)获得(TAG_PRICE_DRY)的ToString();
price_wash_iron = WashIronList.get(位置)获得(TAG_PRICE_WASH_IRON)的ToString();
price_wash = WashList.get(位置)获得(TAG_PRICE_WASH)的ToString();
price_iron = IronList.get(位置)获得(TAG_PRICE_IRON)的ToString();
如果(Cat_Position == 0){
//设置项目名称
ItemName.setText(+姓名);
ItemPrice.setText(+ Price_DryRS);
}否则如果(Cat_Position == 1){
//设置项目名称
ItemName.setText(+姓名);
ItemPrice.setText(RS+ price_iron);
}否则如果(Cat_Position == 2){
//设置项目名称
ItemName.setText(+姓名);
ItemPrice.setText(RS+ price_wash);
}否则如果(Cat_Position == 3){
//设置项目名称
ItemName.setText(+姓名);
ItemPrice.setText(RS+ price_wash_iron);
} 返回convertView;
} }}
解决方案
定义ArrayList的全球和调用Web服务为:
如果(catListDao.size()0){
适配器=新ExpertViewAdapter(ACT,R.layout.custom_expert,catListDao);
list.setAdapter(适配器);
list.setTextFilterEnabled(真);
}其他{ 如果(!isViewShown){
新FetchAllData(getActivity(),2,10,0).execute();
}
}
}
I am working on laundry app. I have a listview
(Fragment
) like this so user can select the items.
My Problem is when I click the continue and then I come back to this screen again its value become zero. How can I save listview state.
I tried this code in my fragment but no luck. And also try save and restore instance state method but facing same problem.
// 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;
}
}
}
解决方案
Define Arraylist globally and call webservices as:
if (catListDao.size() > 0) {
adapter = new ExpertViewAdapter(act, R.layout.custom_expert, catListDao);
list.setAdapter(adapter);
list.setTextFilterEnabled(true);
} else {
if (!isViewShown) {
new FetchAllData(getActivity(), 2, 10, 0).execute();
}
}
}
这篇关于动态列表视图保存状态的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文