【发布时间】：2015-09-13 03:56:18
【问题描述】：
我正在创建一个应用程序，我在其中使用 Json 解析来解析数据。我已经实现了 listview，在我的回复中我有 totalpage 和 current page 对象，
新用户将从第一页获取项目。当用户在列表视图中滚动时，列表会随着来自下一页（以及下一个和下一个等）的项目展开。
这是我的回应 http://pastie.org/10259792
以下是我试过的代码：
首页片段
public class HomeFragment extends Fragment {
// Listview Adapter
ListViewAdapter adapters;
// Connection detector
ConnectionDetector cd;
// Alert dialog manager
AlertDialogManager alert = new AlertDialogManager();
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONparserr jsonParser = new JSONparserr();
ArrayList<HashMap<String, String>> WebsiteList;
// albums JSONArray
JSONArray data = null;
String link_url;
ArrayList<HashMap<String, String>> arrayTemplist;
private AutoCompleteTextView inputSearch;
private ListView lv;
private static final String URL_ALBUMS = "";
private static final String WEBSITE_MENU_ID ="Brand_name";
private static final String TAG_MATCH="data";
//private static final String TAG_NAME="Brand_name";
private static final String TAG_PROFILE="id";
private static final String TAG_CAST="Company";
public HomeFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
lv = (ListView)rootView.findViewById(R.id.listpehlu);
cd = new ConnectionDetector(getActivity());
WebsiteList = new ArrayList<HashMap<String, String>>();
// Loading Albums JSON in Background Thread
new LoadAlbums().execute();
// get listview
inputSearch = (AutoCompleteTextView)rootView.findViewById(R.id.autoCompleteTextViewhomefrag);
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
arrayTemplist= new ArrayList<HashMap<String,String>>();
String searchString =inputSearch.getText().toString().toLowerCase();
for (int i = 0; i < WebsiteList.size(); i++)
{
String currentString =WebsiteList.get(i).get(HomeFragment.this.WEBSITE_MENU_ID);
if (currentString.toLowerCase().startsWith(searchString ))
{
arrayTemplist.add(WebsiteList.get(i));
}
}
for (int i = 0; i < arrayTemplist.size(); i++)
{
String currentstrin = arrayTemplist.get(i).get(HomeFragment.this.WEBSITE_MENU_ID);
//Toast.makeText(getApplicationContext(), currentstrin, Toast.LENGTH_LONG).show();
}
SimpleAdapter adapters = new SimpleAdapter(getActivity(), arrayTemplist,R.layout.list_item_match, new String[] {WEBSITE_MENU_ID,TAG_CAST
}, new int[] {
R.id.txtbrndnm,R.id.txtbrndcomp});
lv.setAdapter(adapters);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
}
});
lv.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position,
long arg3) {
Selected_Product_Listing tf = new Selected_Product_Listing();
Bundle bundle = new Bundle();
bundle.putString("prducts_name", WebsiteList.get(position).get((WEBSITE_MENU_ID)));
// bundle.putString("prducts_name", aList.get(position).get(INTEREST_ACCEPT_NAME));
tf.setArguments(bundle);
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.frame_container, tf);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack(null);
ft.commit();
// Toast.makeText(getActivity(),"lets"+ WebsiteList.get(position).get(convertToBase64(convertToBase64(WEBSITE_MENU_ID))), Toast.LENGTH_LONG).show();
}
});
lv.setOnScrollListener(new OnScrollListener() {
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
if(firstVisibleItem+visibleItemCount == totalItemCount && totalItemCount!=0)
{
}
}
});
return rootView;
}
public String convertToBase64(String text) {
byte[] data = null;
try {
data = text.getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return Base64.encodeToString(data, Base64.DEFAULT);
}
class LoadAlbums extends AsyncTask<String, String, String> {
private JSONObject jsonObj;
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading...");
pDialog.setIndeterminate(true);
pDialog.setIndeterminateDrawable(getResources().getDrawable(R.drawable.custom_progress));
pDialog.setCancelable(false);
pDialog.show();
}
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
String json = jsonParser.makeHttpRequest(URL_ALBUMS, "GET",
params);
// Check your log cat for JSON reponse
Log.d("Albums JSON: ", "> " + json);
if (json != null) {
try {
jsonObj = new JSONObject(json);
// Getting JSON Array node
data = jsonObj.getJSONArray(TAG_MATCH);
String totpage=jsonObj.getString("total_page");
System.out.println("Total Page"+totpage);
String curpage=jsonObj.getString("current_page");
System.out.println("Total Page"+curpage);
// looping through All Contacts
for (int i = 0; i < data.length(); i++) {
JSONObject c = data.getJSONObject(i);
HashMap<String, String> map = new HashMap<String, String>();
map.put(WEBSITE_MENU_ID,c.getString(WEBSITE_MENU_ID));
map.put(TAG_PROFILE, c.getString(TAG_PROFILE));
map.put(TAG_CAST, c.getString(TAG_CAST));
WebsiteList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all albums
pDialog.dismiss();
// updating UI from Background Thread
ListAdapter adapter = new SimpleAdapter(
getActivity(), WebsiteList,
R.layout.list_item_match, new String[] {WEBSITE_MENU_ID,TAG_CAST
}, new int[] {
R.id.txtbrndnm,R.id.txtbrndcomp});
lv.setAdapter(adapter);
}
}
无尽适配器
public class EndLessAdapter extends ArrayAdapter<String> {
private Context context;
private List<String> items;
private int layoutId;
public EndLessAdapter(Context context, List<String> items, int LayoutId) {
super(context,LayoutId,items);
this.context = context;
this.items = items;
this.layoutId = LayoutId;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null)
convertView = ((LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(layoutId,parent,false);
TextView tView = (TextView)convertView.findViewById(R.id.txt);
tView.setText(items.get(position));
return convertView;
}
}
EndlessLisView
public class EndlessListView extends ListView implements OnScrollListener {
private Context context;
private View footer;
private boolean isLoading;
private EndLessListener listener;
private BaseAdapter adapter;
public EndlessListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.setOnScrollListener(this);
this.context = context;
}
public EndlessListView(Context context, AttributeSet attrs) {
super(context, attrs);
this.setOnScrollListener(this);
this.context = context;
}
public EndlessListView(Context context) {
super(context);
this.setOnScrollListener(this);
this.context = context;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
// 4
public void addNewData() {
this.removeFooterView(footer);
// adapter.addAll(products);
adapter.notifyDataSetChanged();
isLoading = false;
}
public void setLoading()
{
isLoading = false;
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) {
if(getAdapter() == null)
return;
if(getAdapter().getCount() == 0)
return;
int l = visibleItemCount + firstVisibleItem;
System.out.println("List View Total Item Count = "+totalItemCount+" , l = "+l+", is_loading = "+isLoading);
if(l >= totalItemCount && !isLoading){
// add footer layout
this.addFooterView(footer);
// set progress boolean
isLoading = true;
System.out.println("$$$$$$$$$ call loaddata $$$$$$$$$$$");
// call interface method to load new data
listener.loadData();
}
}
// Calling order from MainActivity
// 1
public void setLoadingView(int resId) {
footer = ((LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(resId, null); // footer = (View)inflater.inflate(resId, null);
this.addFooterView(footer);
System.out.println("addfooter ====@@@@@@");
}
// 2
public void setListener(EndLessListener listener) {
this.listener = listener;
}
// 3
public void setAdapter(BaseAdapter adapter) {
super.setAdapter(adapter);
this.adapter = adapter;
this.removeFooterView(footer);
}
public void removeFooter(){
this.removeFooterView(footer);
}
}
【问题讨论】：
-
那么，你的问题是什么？你遇到了什么错误？
-
在此处出现错误应用程序崩溃 listener.loadData();
-
查看 ViewHolder 模式
-
@EpicPandaForce 我想得到你
-
@Roman 您尝试实现的内容称为延迟加载或分页。您能否发布处理此问题的整个代码？
标签： android json android-listview endlessscroll