ListView Not Updating After Calling NotifyDataSetChanged()

Asked Dec 25 '16 at 08:07

Active Dec 25 '16 at 08:07

Viewed 46 times

This is My Activity(pActivity5)-

    BackgroundWorker backgroundWorker=new BackgroundWorker(pActivity5.this,this);
    backgroundWorker.execute(type,str1);

    arrayList1.clear();
    arrayList2.clear();

    sharedPreferences=getSharedPreferences("p_name_tech_1",MODE_PRIVATE);

    int a=sharedPreferences.getInt("s_o_a",0);

    for(int i=0;i<a;i++){
        arrayList1.add(i,sharedPreferences.getString(""+i,"null"));
    }
    for(int i=a;i<(a*2);i++){
        arrayList2.add((i-a),sharedPreferences.getString(""+i,"null"));
    }

    adapter=new Adapter(this,arrayList1,arrayList2);
    adapter.notifyDataSetChanged();
    lv1.setAdapter(adapter);

This is my onPostExecute method in BackgroundWorker Class-

        intent = new Intent(context, pActivity5.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        context.startActivity(intent);

When I use backgroundWorker.execute(type,str1).get(); then it works fine but that Defeats the purpose of AsyncTask. So I want to use AsyncTask and update my ListView on its completion.

I have even tried this- How to get the result of OnPostExecute() to main activity because AsyncTask is a separate class? but no success.

edited May 23 '17 at 12:00

Community

asked Dec 25 '16 at 08:07

Avinash Saran

Why not using `lv1.setAdapter(adapter);` in `onPostExecute` ? – ρяσѕρєя K Dec 25 '16 at 08:10
@ρяσѕρєяK because both are in different Class – Avinash Saran Dec 25 '16 at 08:14
@AvinashSaran What is wrong the solution in the SO thread that you have mentioned in your post? – K Neeraj Lal Dec 25 '16 at 08:28
@AvinashSaran: pass lv1 to backgroundWorker class – ρяσѕρєя K Dec 25 '16 at 08:31
@AvinashSaran create a callback inside onPostExecute to your pActivity5 and then update your listview – sohan shetty Dec 25 '16 at 08:33
@sohanshetty It's giving null pointer exception – Avinash Saran Dec 25 '16 at 08:56
@sohanshetty I wrote this in onPostExecute() after context.startActivity(intent); --- ArrayList arrayList=new ArrayList(); ArrayList arrayList1=new ArrayList(); arrayList.add(0,"avinash"); arrayList1.add(0,"saran"); pActivity5 pActivity5=new pActivity5(); pActivity5.adapter=new Adapter(context,arrayList,arrayList1); pActivity5.lv1.setAdapter(pActivity5.adapter); – Avinash Saran Dec 25 '16 at 09:12
@ρяσѕρєяK I am getting null pointer exception – Avinash Saran Dec 25 '16 at 09:43
@AvinashSaran you shouldn't do it like above approach it is wrong and you cannot create object for activity class – sohan shetty Dec 25 '16 at 11:01
@sohanshetty then what should I do? – Avinash Saran Dec 25 '16 at 11:04
post your Backgroundworker class i will tell you – sohan shetty Dec 25 '16 at 11:04

ListView Not Updating After Calling NotifyDataSetChanged()

0 Answers0