Question

I am using Sectioned List in my activity which extends ListActivity
but now as i need to add Actionbar to this activity so i cant use ListActivity here.
So i am trying to use ListView for the same.
But i am not getting how to set adapter to the Listview.
Because i need to set custom adapter used for SectionedListView.
But when i used it for simple ListView it gives NullPointer Exception.
i had wasted more than enough time for it
please help me.

this is the xml file of ListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >
    </ListView>

</LinearLayout>

and this is the adapter used for (ListActivity).


public class EntryAdapter extends ArrayAdapter<Item> {

    private Context context;
    private ArrayList<Item> items;
    private LayoutInflater vi;
    private ImageDownloader mImageDownloader;
    public EntryAdapter(Context context,ArrayList<Item> items, ImageDownloader mImageDownloader) {
        super(context,0, items);
        this.context = context;
        this.items = items;
        vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        this.mImageDownloader = mImageDownloader;
    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        Log.v("position in entry adapter", ""+position);

        final Item i = items.get(position);
        if (i != null) {
            if(i.isSection()){
                SectionItem si = (SectionItem)i;
                v = vi.inflate(R.layout.list_item_section, null);

                v.setOnClickListener(null);
                v.setOnLongClickListener(null);
                v.setLongClickable(false);

                final TextView sectionView = (TextView) v.findViewById(R.id.list_item_section_text);
                sectionView.setText(si.getTitle());
            }else{
                EntryItem ei = (EntryItem)i;
                v = vi.inflate(R.layout.list_item_entry, null);
                final TextView title = (TextView)v.findViewById(R.id.list_item_entry_title);
                final TextView subtitle = (TextView)v.findViewById(R.id.list_item_entry_summary);
                final ImageView cat_icon = (ImageView)v.findViewById(R.id.category_icon);
                final ImageView channel_icon = (ImageView)v.findViewById(R.id.channel_icon);
                if (title != null) 
                    title.setText(ei.title);
                if(subtitle != null)
                    subtitle.setText(ei.subtitle);
                if(cat_icon != null)
                {
                    if(ei.catIcon != null)
                        cat_icon.setImageBitmap(ei.catIcon);
                    else
                        cat_icon.setVisibility(View.INVISIBLE);
                }
                if(channel_icon !=null)
                {
                    if(ei.url != null)
                    {
                        mImageDownloader.download(ei.url,channel_icon);
                        Log.v("url in adapter", ei.url);
                    }
                    else
                        channel_icon.setVisibility(View.INVISIBLE);
                }
            }
        }
        return v;
    }


}



mList = (ListView) findViewById(R.id.list);

EntryAdapter adapter = new EntryAdapter(this, items, mImageDownloader);
        mList.setAdapter(adapter);
        mList.setOnItemClickListener(this);

Thanks
Mahaveer.

Answer 1

What you need to do for changing a class that extends ListActivity to Activity,

1.) Extend your Class with Activity instead of ListActivity

2.) Change the id of ListView in xml from @android:id/list to @+id/your_listview

3.) find the instance of ListView declared in xml using

ListView your_listview = (ListView)findViewById(R.id.your_listview);  

4.) Set the Adapter using,
your_listview.setAdapter(adapter);