Question

base adapter code

public class ListAdapter extends BaseAdapter{

public ArrayList<HashMap<String,String>> list;
Activity activity;

public ListAdapter(Activity activity, ArrayList<HashMap<String, String>>list ) {
    // TODO Auto-generated constructor stub
    super();
    this.activity=(Activity)activity;
    this.list=list;
    for(int i=0;i<3;i++)
    {
        HashMap<String, String>temp=(HashMap<String, String>)list.get(i);
        System.out.println(temp.get("message"));
        System.out.println(temp.get("from_whom"));          
    }
}

public int getCount() {
    // TODO Auto-generated method stub
    list.size();
    return 0;
}

public Object getItem(int position) {
    // TODO Auto-generated method stub
    return list.get(position);
}

public long getItemId(int arg0) {
    // TODO Auto-generated method stub
    return 0;
}
private class ViewHolder {
       TextView Message;
       TextView fromWhom;
  }

public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    ViewHolder holder;
    LayoutInflater inflater =  activity.getLayoutInflater();
    if (convertView == null)
    {   
        convertView = inflater.inflate(R.layout.custom_list_view, null);
        holder = new ViewHolder();
        holder.Message = (TextView) convertView.findViewById(R.id.message);
        holder.fromWhom = (TextView) convertView.findViewById(R.id.fromWhom);
        convertView.setTag(holder);
    }
    else
    {
        holder = (ViewHolder) convertView.getTag();
    }
    HashMap<String, String> item = list.get(position);
    String message = item.get("message");
    String from_whom = item.get("from_whom");
    holder.Message.setText(message);
    holder.fromWhom.setText(from_whom);
    return convertView;

}
}

main class code

 public class go_on extends Activity 
{
    ListView list;
    ArrayList<String> nlist;
    ArrayList<HashMap<String, String>> Hlist;
    HashMap<String, String> temp;
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        list = (ListView)findViewById(R.id.mylist);
        Hlist = new ArrayList<HashMap<String,String>>();
        for(int i=0;i<3;i++)
        {
            temp= new HashMap<String, String>();
            temp.put("message","I am fine");
            temp.put("from_whom", "123");
            Hlist.add(temp);
        }

        ListAdapter listAdapter = new ListAdapter(this, Hlist);
        list.setAdapter(listAdapter);       
    }

}

But list does not come . I could not find any problem. Please help me out.

Answer 1

You are returning zero in count.

public int getCount() {
    // TODO Auto-generated method stub
    list.size();
    return 0;
}

You have return list.size(). Change it lke this,

public int getCount() {
    // TODO Auto-generated method stub

    return  list.size();
}

getCount() is the method which informs your Adapter about the number of elements that has to be inflated. When you return zero it means that there is no elements present and hence you are unable to see your listview.