adding view on the bottom of listview

Question

After inizializing the custom adapter for my ListView it draw the first part of the dataset. Now I want to add some other view at the bottom of the listview. But when i use notifyDataSetChanged it doesn't refresh the listview.

setup

                ListView messages = findViewById(R.id.latest_messages);


                adapter = new AdapterChat(getApplicationContext(),
                        R.layout.element_chat_other, inputItems);


                messages = (ListView) findViewById(R.id.messages);
                messages.setAdapter(adapter);
                messages.setSmoothScrollbarEnabled(true);

update not working:

i add a new object in the arraylist and then recall the adapter for refreshing data. But view still not showing:

                inputItems.add(new DTOChat(fromCC,messageCC, tsCC, idCC));
                adapter = new AdapterChat(getApplicationContext(),
                        R.layout.element_chat_other, inputItems);


                adapter.notifyDataSetChanged();

ADAPTER

public class AdapterChat extends ArrayAdapter<DTOChat > {

Context context;
int rand = 0;

public AdapterChat(Context context, int risorsaId,
                   List<DTOChat> items) {
    super(context, risorsaId, items);
    this.context = context;
}




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

    //controllo se c'è gia un layout
    LayoutInflater mInflater = (LayoutInflater) context
            .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);

    final DTOChat content = getItem(position);

    SharedPreferences preferences = getContext().getSharedPreferences("pref", Context.MODE_PRIVATE);
    String username = preferences.getString("username", "");

    if(content.getFrom().toLowerCase().equals(username.toLowerCase())) {
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.element_chat_other, null);
        }
    } else {
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.element_chat_me, null);
        }
    }

    final TextView msg = convertView.findViewById(R.id.msg);
    msg.setText(content.getMessage());


    //data
    TextView ts = convertView.findViewById(R.id.ts);
    String[] chunks = content.getTs().split(" ");
    String[] chunks2 = chunks[1].split(":");
    ts.setText(chunks2[0]+":"+chunks2[1]);




    return convertView;

}

}

Answer 1

try like this

inputItems.add(new DTOChat(fromCC,messageCC, tsCC, idCC));
// here no need to create new adapter instance only add below line
adapter.notifyDataSetChanged();

Answer 2

With the following statement, you assign an instance of AdapterChat to adapter

adapter = new AdapterChat(getApplicationContext(),
                    R.layout.element_chat_other, inputItems);

Then you set this instance as adapter for the ListView

messages.setAdapter(adapter);

Some time later, you add a new item to the data list inputItems and assign another instance of AdapterChat to adapter

inputItems.add(new DTOChat(fromCC,messageCC, tsCC, idCC));
adapter = new AdapterChat(getApplicationContext(),
                    R.layout.element_chat_other, inputItems);

Now, the old instance is still set as the current ListView adapter but when you call adapter.notifyDataSetChanged(); you notify the recently created instance which you assigned to adapter.

You can keep adapter the way it is (don't create a new instance), simply add the new item to inputItems and directly afterwards call

adapter.notifyDataSetChanged();