Android AsyncTask and progress bars

Question

I have a problem in My android app, I searched too much but i couldn't find a clue for solving it. this is my problem

I have a list view , onclick on each of the list items i start a new AsyncTask which update the a progress bar in the list item.

the problem comes when the system destroys my activity for any reasons, the AsyncTasks remain working but it doesn't affect the newly created progress bars,

any one can help me ? Thanks in advance.

do you want AsyncTasks to be destroyed on Activity finishes? — AAnkit, Aug 26 '13 at 08:54
no, i need it to continue working and after the activity is recreated update the new progressbars — Omar Hassan, Aug 26 '13 at 08:58
it can not be done, better you use service, if you want it to keep working even after Activity is not in the front. — AAnkit, Aug 26 '13 at 09:00
services couldn't be executed on parallel,one instance only of the service could be active at time, but tasks could run in parallel. — Omar Hassan, Aug 26 '13 at 09:03

Abhishek Birdawade · Accepted Answer · 2013-08-26T11:20:28.640

I was suffering from the same problem then what i have done is i was having a Serializable class in which data for the listview is stored and in that class i created a variable named

int progress;

When anything gets updated from asynsTask i set the updates to this variable which is unique for each row because of serializable class and object.Here is the example -:

Content.java

 public class Content implements Serializable {

            @SerializedName("id")
            protected String id;

            protected int progress = -1;

            public String getId() {
                   return id;
            }

            public String setId(String id) {
                   this.id = id;
            }

            public int getProgress() {
                   return progress;
            }

            public void setProgress(int progress) {
                   this.progress = progress;
            }
    }

MainActivity.java -:

AsyncAdapter -:

    public class AsyncAdapter extends ArrayAdapter<Content>   {

    Context context;
    ArrayList<Content> items;
    private static final int TYPE_MAX_COUNT = 1;

    public AsyncAdapter(Context context, int resource,
            int textViewResourceId, ArrayList<Content> items) {
        super(context, resource, textViewResourceId, items);
        this.context = context;
        this.items = items;
    }

    public int getViewTypeCount() {
        return TYPE_MAX_COUNT;
    }

    @Override
    public View getView(final int position, View convertView,
            ViewGroup parent) {

                 // Layout inflate code

                 // if else condition to visible progress bar
                 viewHolder.progressbar.setProgress(content.getProgress(position));

                 viewHolder.downloadButton
                        .setOnClickListener(new OnClickListener() {

                            @Override
                            public void onClick(View arg0) {
                 //Start service here
                 Intent serviceIntent = new Intent(MainActivity.this,DownloadService.class);
                 serviceIntent.putExtra("id",id);
                 startService(serviceIntent);

            }});
    }
 }

In your BroadCastReceiver, you can set the progress and can update progress of progressbar.

public class DownloadReceiver extends BroadcastReceiver {


@Override
public void onReceive(Context context, final Intent intent) {

    final int progress = intent.getIntExtra("progress", 0);
    final String broadcastId = intent.getStringExtra("id"); 

  for(int i=0;i<contents.size();i++) {
        if(contents.getId().equals(broadcastId)) {
             contents.get(i).setProgress(progress);
        }
   }

   adapter.notifyDataSetChanged(); // to update progressbar and listview
  removeStickyBroadcast(intent);
 }

And from service you can send the progress to receiver and can update it simultaneously.I think this is the better option instead of using asynTask.To add data in Content you will either have parse it and add using gson or add it explicitely.I hope this helps you and you will get better idea how to handle progressbars within listview.

could you share any example for this solution ? – Omar Hassan Aug 26 '13 at 10:16 — Omar Hassan, Aug 26 '13 at 10:16

score 0 · Answer 2 · answered Aug 26 '13 at 08:59

0

Create one callback listener method and override it in your activity.Call this callback method from onProgressUpdate in AsynkTask.and update the progress bar.

answered Aug 26 '13 at 08:59

kirankk

628
1
9
22

the progressbars are holded by the list adapter data model. – Omar Hassan Aug 26 '13 at 09:01
But each progress bar can be accessed from adapter – kirankk Aug 26 '13 at 09:03
so you can update the progress bar after recreation of activity. – kirankk Aug 26 '13 at 09:08
make progress bar static – kirankk Aug 26 '13 at 09:14
the progress bar is destroyed and recreated again after recreating the activity. – Omar Hassan Aug 26 '13 at 10:48

score 0 · Answer 3 · edited May 23 '17 at 10:32

0

I think this Post can help you. But this is particularly for that case where your activity is recreated due to Configuration change.

edited May 23 '17 at 10:32

Community

1
1

answered Aug 26 '13 at 09:33

Syamantak Basu

905
4
10
20

Android AsyncTask and progress bars

3 Answers3