update listview in my activity from service android

Question

I having 2 classes ,

1.Activity class

2.Service class

I need to update my list view in my activity,when service got any updates. Actually i trying like an chat application , My services always checking my db and if it got any new string , i need to update in my activity without rebuild the again only i need to refresh the list view. i found it will be manipulated using iBinder , But i don't how to use it. Can any one suggest me with some examples of code .

referred pages

Answer 1

You should use a Bound Service. I did the something similar in my application. Where upon clicking refresh, I invoke a service which gets data in background and updates the UI.

Check out my service here: https://github.com/madhur/GAnalytics/blob/develop/src/in/co/madhur/ganalyticsdashclock/AnalyticsDataService.java

@Override
protected void onPostExecute(AnalyticsAccountResult result) {
    super.onPostExecute(result);
    App.getEventBus().post(result);
}

Activity: https://github.com/madhur/GAnalytics/blob/develop/src/in/co/madhur/ganalyticsdashclock/MainActivity.java

@Subscribe
public void UpdateUI(AnalyticsAccountResult result) {
    ProgressBar progressbar = (ProgressBar) findViewById(R.id.pbHeaderProgress);
    LinearLayout spinnerLayout = (LinearLayout) findViewById(R.id.spinnerslayout);
    TextView statusMessage = (TextView) findViewById(R.id.statusMessage);

    switch (result.getStatus()) {
        case STARTING:
        statusMessage.setVisibility(View.GONE);
        progressbar.setVisibility(View.VISIBLE);
        spinnerLayout.setVisibility(View.GONE);
        break;

        case FAILURE:
        statusMessage.setVisibility(View.VISIBLE);
        progressbar.setVisibility(View.GONE);
        spinnerLayout.setVisibility(View.GONE);
        statusMessage.setText(result.getErrorMessage());
        break;

        case SUCCESS:
        statusMessage.setVisibility(View.GONE);
        progressbar.setVisibility(View.GONE);
        spinnerLayout.setVisibility(View.VISIBLE);

        if (result.getItems() != null)
        {
            this.acProfiles = result.getItems();
            MyAdapter myAdapter = new MyAdapter(acProfiles, this);
            listView.setAdapter(myAdapter);
            UpdateSelectionPreferences();
            if (result.isPersist() && acProfiles.size() > 0)
            {
                if (App.LOCAL_LOGV)
                Log.v(App.TAG, "saving configdata");        
                try
                {
                    appPreferences.saveConfigData(acProfiles, credential.getSelectedAccountName());
                }
                catch (JsonProcessingException e)
                {
                    Log.e(App.TAG, e.getMessage());
                }
            }
        }
        break;
    }
}

It would also helpful to use Otto library:
http://square.github.io/otto/

Answer 2

Without more information I cannot provide any useful code examples, however I think what you may be looking for is a ListAdapter. A ListAdapter takes a listview and a dataset (in your case maybe an array of strings) and combines the 2. Whenever the dataset changes (in your case this would be when your service detects a new string and adds it to the array) you just call ListAdapter.notifyDataSetChanged() and the listview will be automatically updated with your new information. Check http://developer.android.com/reference/android/widget/ArrayAdapter.html for more info on the specific ListAdapter you might use.

Answer 3

Let's suppose you have the activity class named MainActivity where you initialized your ListView with the adapter named listviewAdapter. Put this code inside MainActivity:

  public static Handler UIHandler;

    static {
        UIHandler = new Handler(Looper.getMainLooper());
    }

    public static void runOnUI(Runnable runnable) {
        UIHandler.post(runnable); 
    }

When you made changes to your listview data inside your service class, write this code to apply new data to the ListView:

MainActivity.runOnUI(new Runnable()
{
    public void run()
    {
        try
        {
            MainActivity.listviewAdapter.notifyDataSetChanged();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
});