我有一个包含自定义布局的列表视图。我正在从服务器中检索数据并在列表视图视图中显示它。
我正在使用Pull to refresh listview库
提供互联网连接---＆gt;当我拉动刷新时，数据成功更新
没有互联网连接---＆gt;当我拉动刷新时，现有数据消失，使listview为空，这不是预期的
当没有可用的互联网连接时，我希望现有数据仍然可见。
HomeFragent.java
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.listview_layout, container,false);
View footer_image=inflater.inflate(R.layout.listview_image_footer, null,false);
//footer_image.setClickable(false);
/* get theme webservice*/
StrictMode.ThreadPolicy policy1 = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy1);
userFunction=new UserFunctions();
//Breaking News Section
slide = AnimationUtils.loadAnimation(getActivity(), R.anim.slidedown);
fadeOut = AnimationUtils.loadAnimation(getActivity(), R.anim.fadeout);
pan_breaking_new = (LinearLayout)rootView.findViewById(R.id.pan_breaking_new);
//pan_breaking_new.setOnClickListener(this);
pan_breaking_new.setVisibility(8);
btn_close= (ImageView) rootView.findViewById(R.id.btn_close);
btn_close.setOnClickListener(this);
img_share= (ImageView) rootView.findViewById(R.id.img_share);
img_share.setOnClickListener(this);
//END Breaking News Section
//Ticker
marque = (ScrollingTextView)rootView.findViewById(R.id.txtTicker);
marque.setVisibility(8);
//END ticker
main_error = (TextView) rootView.findViewById(R.id.main_error);
main_error.setText("Loading...");
img_error = (ImageView) rootView.findViewById(R.id.img_error);
img_error.setOnClickListener(this);
progressBar1 = (ProgressBar) rootView.findViewById(R.id.progressBar1);
progressBar1.setVisibility(8);
//karthik
refreshable_listView = (PullToRefreshListView) rootView.findViewById(R.id.listView);
listView=refreshable_listView.getRefreshableView();
listView.addFooterView(footer_image, null, false);
refreshable_listView.setOnRefreshListener(new OnRefreshListener<ListView>() {
@Override
public void onRefresh(PullToRefreshBase<ListView> refreshView) {
// TODO Auto-generated method stub
listView=refreshable_listView.getRefreshableView();
try {
getTheme();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
new GetList().execute(index_th);
}
});
newsList = new ArrayList<HashMap<String, String>>();
mAdapter = new MyCustomAdapter(getActivity(), newsList);
refreshable_listView.setAdapter(mAdapter);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View view, int arg2,
long arg3) {
news_flag= (TextView) view.findViewById(R.id.flag);
news_id = (TextView) view.findViewById(R.id.fid);
news_live = (TextView) view.findViewById(R.id.live);
news_title_live = (TextView) view.findViewById(R.id.title);
//news_flag.getText().toString();
//Log.e("-->", news_flag.getText().toString());
//checking for click banner or neews
if(news_flag.getText().toString().equals("normal")){
// Starting a new async task
new ViewSingleNews().execute();
}else{
/*Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse(All_link.IMAGE_URI_BANNER+news_flag.getText().toString()),"image/*");
startActivity(intent);*/
}
}
});
listView.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
int count = Integer.parseInt(index_temp)+6;
System.out.println("Checking "+ listView.getLastVisiblePosition());
System.out.println("----->Checking loadmore:"+ load_more);
System.out.println("----->Checking actual:"+ count);
if (listView.getLastVisiblePosition()+1 == count) {
if(load_more==1){
index_temp = String.valueOf(Integer.parseInt(icount) + Integer.parseInt(index_temp));
new GetList_ontouch().execute(index_temp);
}
}
}
});
//listView.addHeaderView(pan_breaking_new);
mSeparatorsSet = new TreeSet<Integer>();
mSeparatorsSet_alternate_layout = new TreeSet<Integer>();
mSeparatorsSet_live_layout = new TreeSet<Integer>();
new GetList_img_error().execute(index_th); // same as GetList(), but displays dialog
return rootView;
}
private class GetList extends AsyncTask<String, Void, Void> {
Dialog dialog = new Dialog(getActivity());
String jsonStr;
ArrayList<HashMap<String, String>> Local_newsList;
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(String... params) {
if (NetworkCheck.isNetworkAvailable(getActivity()) == true) {
//Log.d("index count for array", params[0]);
if(Integer.parseInt(params[0])==0){
//Log.d("index count for array","Rweached");
//newsList = new ArrayList<HashMap<String, String>>();
}
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
jsonStr = sh.makeServiceCall(All_link.HOME_DATA_URL + "/"+params[0]+"/"+ icount,
ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
news = jsonObj.getJSONArray(All_link.TAG_NEWS);
err = jsonObj.getString(All_link.TAG_ERROR);
String more = jsonObj.getString(All_link.TAG_MORE);
Log.e("------>Error",String.valueOf(err));
Log.e("------>More",String.valueOf(more));
if(more.equals("0")){
load_more = 0;
}else{
load_more = 1;
}
// looping through All Contacts
for (int i = 0; i < news.length(); i++) {
//karthik
JSONObject segments_list = news.getJSONObject(i);
for (int plates_count = 0; plates_count < segments_list
.length(); plates_count++) {
String plates = "";
if (plates_count == 3) {
plates = String.valueOf("banner_image");
JSONObject segments_plates = segments_list
.getJSONObject(plates);
//String flag = "banner_image";
String id = segments_plates
.getString(All_link.TAG_BANNER_ID);
String banner_no = segments_plates
.getString(All_link.TAG_BANNER_NO);
String banner_image;
if(segments_plates.getString(All_link.TAG_BANNER_THUMB_URL)==""){
banner_image = All_link.TAG_NO_IMAGE;
}else{
banner_image = segments_plates.getString(All_link.TAG_BANNER_THUMB_URL);
}
String banner_status = segments_plates
.getString(All_link.TAG_BANNER_STATUS);
// tmp hashmap for single news
HashMap<String, String> news_hashmap = new HashMap<String, String>();
// adding each child node to HashMap key =>
// value
news_hashmap.put(All_link.TAG_BANNER_ID, id);
news_hashmap.put(All_link.TAG_BANNER_NO,
banner_no);
news_hashmap.put(All_link.TAG_BANNER_THUMB_URL,
banner_image);
news_hashmap.put(All_link.TAG_BANNER_STATUS,
banner_status);
/*news_hashmap
.put(All_link.TAG_BANNER_FLAG, flag);*/
// adding contact to contact list
newsList.add(news_hashmap);
//karthik newsList
//Local_newsList.add(news_hashmap);
addSeparatorItem();
} else {
plates = String.valueOf(plates_count + 1);
JSONObject segments_plates = segments_list
.getJSONObject(plates);
if(segments_plates.getString(All_link.TAG_NEWS_TYPE).equals("2")){
//type_of_news = segments_plates.getString(All_link.TAG_NEWS_TYPE);
addSeparatorItem_for_live();
}
String id = segments_plates.getString(All_link.TAG_ID);
String news_title = segments_plates.getString(All_link.TAG_NEWS_TITLE);
String news_desc = segments_plates.getString(All_link.TAG_DESC);
String segment = segments_plates.getString(All_link.TAG_SEGMENT);
String plate = segments_plates.getString(All_link.TAG_PLATE);
String img ="";
if(segments_plates.getString(All_link.TAG_THUMB_URL).equals("")){
img = All_link.TAG_NO_IMAGE;
}else{
img = segments_plates.getString(All_link.TAG_THUMB_URL);
}
HashMap<String, String> news_hashmap = new HashMap<String, String>();
// adding each child node to HashMap key =>
// value
news_hashmap.put(All_link.TAG_ID, id);
news_hashmap.put(All_link.TAG_NEWS_TITLE, news_title);
news_hashmap.put(All_link.TAG_DESC, news_desc);
news_hashmap.put(All_link.TAG_SEGMENT, segment);
news_hashmap.put(All_link.TAG_PLATE, plate);
news_hashmap.put(All_link.TAG_THUMB_URL, img);
//news_hashmap.put(All_link.TAG_BANNER_FLAG, flag);
// adding contact to contact list
newsList.add(news_hashmap);
//karthik newsList
//Local_newsList.add(news_hashmap);
int val = 0;
int val2 = 1;
val = (Integer.parseInt(segment)%2)==0 ? val:val2;
if((Integer.parseInt(segment)%2)!=0){
Log.e("--->CHECKING ODD EVEN", String.valueOf(val));
addSeparatorItem();
addSeparatorItem_for_alternate();
}
}
}
}
} catch (JSONException e) {
Local_newsList=null;
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
} else {
Log.e("Network Error", "Internet Connection Error");
error_flag = 1;
// error = "Internet Connection Error";
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
mAdapter.notifyDataSetChanged();
refreshable_listView.invalidate();
refreshable_listView.requestLayout();
refreshable_listView.onRefreshComplete();
super.onPostExecute(result);
if(error_flag==1){
listView.setVisibility(8);
main_error.setText("Internet Connection Error! Please check your network settings and try again");
main_error.setVisibility(0);
img_error.setVisibility(0);
}else{
listView.setVisibility(0);
main_error.setText("");
main_error.setVisibility(8);
img_error.setVisibility(8);
int currentPosition = listView.getFirstVisiblePosition();
mAdapter = new MyCustomAdapter(getActivity(), newsList);
//testing
listView.setAdapter(mAdapter);
refreshable_listView.setAdapter(mAdapter);
// Setting new scroll position
listView.setSelection(currentPosition);
mAdapter.notifyDataSetChanged();
}
SharedPreferences sharedPrefs = getActivity().getSharedPreferences(All_link.MyPREFERENCES,
Context.MODE_PRIVATE);
sharedPrefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
//For Breaking News Setting
if (sharedPrefs.getInt("prefswtch4", 1) == 1) {
if (All_link.GLOBAL_BREAKING_FLAG == 0) {
new getBreakingNews().execute();
}
}
//For Location Setting
if (sharedPrefs.getInt("prefswtch1", 1) == 1) {
} else {
}
//For Ticker Setting
if (sharedPrefs.getInt("prefswtch2", 1) == 1) {
new getTicker().execute();
} else {
marque.setVisibility(8);
}
}
@Override
protected void onCancelled() {
// TODO Auto-generated method stub
refreshable_listView.onRefreshComplete();
}
}
答案 0 :(得分：1)
最后我解决了这个问题。
我刚刚在SharedPreference中保存了字符串jsonStr，并创建了单独的
class GetList_refresh extends AsyncTask<String, String, Void>
并且当没有网络可用时调用new GetList_refresh().execute(index_th,jsonStr);。
它按预期完美运作......