我在应用程序的一个ViewPager中有Fragment的嵌套标签布局。
每个Fragment嵌套片段都会使用ListView向WebServices显示数据。
public class IndicesFragment extends android.support.v4.app.Fragment {
public static String imagepath = null;
static ArrayList<EquityDetails> catListDao = new ArrayList<EquityDetails>();
static ArrayList<EquityDetails> catListDao1 = new ArrayList<EquityDetails>();
static int count = 0;
static int count1 = 0;
ListView list;
ImageView progressBar;
View view;
Activity act;
AdvisorsAdapter adapter;
TextView empty_text;
private boolean isViewShown = false;
AnimatorSet set;
FetchAllData myTask;
JSONArray jsonArray;
public static IndicesFragment newInstance() {
return new IndicesFragment();
}
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
isViewShown = true;
if (adapter != null) {
adapter.filter("");
}
} else {
isViewShown = false;
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.equity_activity, container, false);
act = this.getActivity();
Constants.check_fragment_visible = 1;
count++;
setHasOptionsMenu(true);
list = (ListView) view.findViewById(R.id.list_equity);
empty_text = (TextView) view.findViewById(R.id.empty);
progressBar = (ImageView) view.findViewById(R.id.progressBar);
set = (AnimatorSet) AnimatorInflater.loadAnimator(getActivity(), R.animator.fadein);
set.setTarget(progressBar);
progressBar.setVisibility(View.GONE);
if (Utils.isNetworkAvailable(getActivity())) {
if (catListDao.size() > 0) {
adapter = new AdvisorsAdapter(act, R.layout.custom_equity, catListDao, 0);
list.setAdapter(adapter);
} else {
if (!isViewShown) {
new FetchAllData(getActivity(), 3).execute();
}
}
} else {
CustomToast toast = new CustomToast(getActivity(), "There is no internet connection!");
}
return view;
}
public void onActivityCreated(Bundle savedInstanceState1) {
super.onActivityCreated(savedInstanceState1);
}
@Override
public void onResume() {
super.onResume();
Constants.check_fragment_visible = 1;
if (Constants.check_reload) {
if (Utils.isNetworkAvailable(getActivity())) {
new FetchAllData(getActivity(), 3).execute();
} else {
CustomToast toast = new CustomToast(getActivity(), "There is no internet connection!");
}
}
if (adapter != null) adapter.notifyDataSetChanged();
}
public void doChange(String queryText) {
if (queryText != null) {
if (adapter != null)
adapter.filter(queryText);
}
}
public class FetchAllData extends AsyncTask<Void, Void, String> {
ProgressDialog pDialog;
int typeId;
private Context cont;
public FetchAllData(Context con, int typeId) {
// TODO Auto-generated constructor stub
this.cont = con;
this.typeId = typeId;
Log.d("Constructor Called", "yes");
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
MainTabFragment.getInstance().myTabLayout.setClickable(false);
progressBar.setVisibility(View.VISIBLE);
set.start();
}
@Override
protected String doInBackground(Void... params) {
// TODO Auto-generated method stub
return getString();
}
private String getString() {
// TODO Auto-generated method stub
URL obj = null;
HttpURLConnection con = null;
try {
obj = new URL(Constants.AppBaseUrl + "/call_listing/" + typeId);
String userPassword = "rickmams" + ":" + "advisor11";
String header = "Basic " + new String(android.util.Base64.encode(userPassword.getBytes(), android.util.Base64.NO_WRAP));
con = (HttpURLConnection) obj.openConnection();
con.addRequestProperty("Authorization", header);
con.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
con.setRequestMethod("POST");
// For POST only - BEGIN
con.setDoOutput(true);
OutputStream os = con.getOutputStream();
os.flush();
os.close();
// For POST only - END
int responseCode = con.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) { //success
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
Log.i("TAG", response.toString());
parseJSON(response.toString());
return response.toString();
} else {
Log.i("TAG", "POST request did not work.");
}
} catch (IOException e) {
e.printStackTrace();
}
if (con != null) {
con.disconnect();
}
return null;
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if (result != null) {
list.setAdapter(adapter);
//pDialog.dismiss();
set.end();
if (progressBar.getVisibility() == View.VISIBLE)
progressBar.setVisibility(View.GONE);
MainTabFragment.getInstance().myTabLayout.setClickable(true);
if (jsonArray.length() != 0) {
empty_text.setVisibility(View.GONE);
} else empty_text.setVisibility(View.VISIBLE);
}
}
}
public void parseJSON(String result) {
if (result != null) {
JSONObject jsonObject;
try {
catListDao = new ArrayList<EquityDetails>();
jsonObject = new JSONObject(result);
jsonArray = jsonObject.getJSONArray("list");
Log.d("Length ", "" + jsonArray.length());
for (int i = 0; i < jsonArray.length(); i++) {
EquityDetails allDirectory = new EquityDetails();
allDirectory.setEntry_value(jsonArray.getJSONObject(i).getString("entry"));
String value1 = jsonArray.getJSONObject(i).getString("entry");
String value2 = jsonArray.getJSONObject(i).getString("tgt_1");
allDirectory.setSerial_value(jsonArray.getJSONObject(i).getString("sl"));
allDirectory.setTg_value1(jsonArray.getJSONObject(i).getString("tgt_1"));
allDirectory.setTg_value2(jsonArray.getJSONObject(i).getString("tgt_2"));
allDirectory.setPosted_by(jsonArray.getJSONObject(i).getString("posted_by"));
allDirectory.setMainTitle_value(jsonArray.getJSONObject(i).getString("script"));
allDirectory.setMain_subTitle_value(jsonArray.getJSONObject(i).getString("exchange"));
allDirectory.setRating_value(jsonArray.getJSONObject(i).getString("rating"));
allDirectory.setReview_value(jsonArray.getJSONObject(i).getString("review"));
imagepath = jsonArray.getJSONObject(i).getString("advisor_image");
Log.d("Comminh Image ", "" + jsonArray.getJSONObject(i).getString("advisor_image"));
allDirectory.setImage1(jsonArray.getJSONObject(i).getString("advisor_image"));
allDirectory.setImage2(jsonArray.getJSONObject(i).getString("script_image"));
allDirectory.setBuy(jsonArray.getJSONObject(i).getString("buy_sentiment"));
allDirectory.setSell(jsonArray.getJSONObject(i).getString("sell_sentiment"));
allDirectory.setRecommend(jsonArray.getJSONObject(i).getString("recommendation"));
allDirectory.setPosted_date(jsonArray.getJSONObject(i).getString("posted_date"));
allDirectory.setCall_id(jsonArray.getJSONObject(i).getString("call_id"));
allDirectory.setExpiry_date(jsonArray.getJSONObject(i).getString("expiry_date"));
allDirectory.setBroker_name(jsonArray.getJSONObject(i).getString("name"));
allDirectory.setProgress_indicator(0);
catListDao.add(allDirectory);
}
catListDao1 = catListDao;
adapter = new AdvisorsAdapter(act, R.layout.custom_equity, catListDao, 0);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
问题是当我们从Fragment更改Activity时应用程序崩溃，当我们从MainActivity的另一个片段调用这个嵌套片段时，它会在那里被冻结，并且嵌套片段的片段在那里突然打开。堆栈跟踪如下：
1-29 12:10:49.580 10853-10863/com.cws.advisorymandi W/art: Suspending all threads took: 10.409ms
01-29 12:10:49.707 10853-10853/com.cws.advisorymandi D/cr_Ime: [InputMethodManagerWrapper.java:27] Constructor
01-29 12:10:49.711 10853-10853/com.cws.advisorymandi D/cr_Ime: [ImeAdapter.java:241] attach
01-29 12:10:49.711 10853-10853/com.cws.advisorymandi W/art: Attempt to remove local handle scope entry from IRT, ignoring
01-29 12:10:49.716 10853-10853/com.cws.advisorymandi W/AwContents: onDetachedFromWindow called when already detached. Ignoring
01-29 12:10:49.717 10853-10853/com.cws.advisorymandi D/cr_Ime: [InputMethodManagerWrapper.java:56] isActive: false
01-29 12:10:49.726 10853-10853/com.cws.advisorymandi W/art: Attempt to remove local handle scope entry from IRT, ignoring
01-29 12:10:49.726 10853-10853/com.cws.advisorymandi W/art: Attempt to remove local handle scope entry from IRT, ignoring
01-29 12:10:49.812 10853-10853/com.cws.advisorymandi D/cr_Ime: [ImeAdapter.java:241] attach
01-29 12:10:49.832 10853-10853/com.cws.advisorymandi D/cr_Ime: [ImeAdapter.java:241] attach
01-29 12:10:49.833 10853-10853/com.cws.advisorymandi I/Choreographer: Skipped 58 frames! The application may be doing too much work on its main thread.
01-29 12:10:50.075 10853-10853/com.cws.advisorymandi W/cr_BindingManager: Cannot call determinedVisibility() - never saw a connection for the pid: 10853
01-29 12:10:50.610 10853-10863/com.cws.advisorymandi W/art: Suspending all threads took: 43.636ms
01-29 12:10:50.621 10853-10853/com.cws.advisorymandi I/Ads: Scheduling ad refresh 60000 milliseconds from now.
01-29 12:10:50.630 10853-10853/com.cws.advisorymandi I/Ads: Ad finished loading.
现在我想通过在Asynctasks的{{1}}和onPause方法中停止并运行这些onResume来解决此问题。谁能告诉我如何克服这个重大问题？
答案 0 :(得分：1)
当我尝试使用2个异步任务时，我遇到了类似的问题。我通过评论toast，printStackTrace和Log来解决了这个问题，特别是在doInBackground()方法中。这个答案可能听起来很奇怪，但你肯定可以尝试一下。