Android: How to add data to an empty listView

Question

Hi everyBody, I have a problem with listView, I used ArrayList to store data, and a customized Adapter. But, when I remove all the data, and add one item again, it does not display anything in this list. What happens to my List, can anyone help me?

static ArrayList<String>  chattingListData=new ArrayList<String>(); 
static IconicAdapter chattingListDataAdapter;

@Override
public void onCreate(Bundle icicle) {

   super.onCreate(icicle);
   chattingListDataAdapter=new IconicAdapter(this);
   setListAdapter(chattingListDataAdapter);
   registerForContextMenu(this.getListView());

}

class IconicAdapter extends ArrayAdapter {

   Activity context;

   IconicAdapter(Activity context) {
      super(context, R.layout.chatting_list, chattingListData);       
      this.context=context;
   }

   public View getView(int position, View convertView, ViewGroup parent) {
      LayoutInflater inflater=context.getLayoutInflater();
      View row=inflater.inflate(R.layout.chatting_list, null);
      TextView label=(TextView)row.findViewById(R.id.chattinglist_userName);
      label.setText(chattingListData.get(position));  
      return(row);
   }
}

I use static ArrayList to modify data from outside, when I start the ListView activity and add data, it's Ok, but when I remove all data, I can not add anymore to the data list. Please help me.

Answer 1

I use static ArrayList to modify data from outside

Don't do that.

Step #1: Use a non-static ArrayList data member as the basis for your ArrayAdapter.

Step #2: Expose methods on your activity that adds and removes items via the add(), insert(), and remove() methods on ArrayAdapter. By using these methods, your ListView will automatically update when you make the changes.

Step #3: Use the methods you wrote in Step #2 to modify the contents of your ListView, by whoever is doing this (not shown in your code).