Why does my listView doesn't show inserted rows?

Question

I have a custom cursorAdapter that is certainly missing something, because when I add a item in the database, it isn't shown on the listView, but if I relaunch the application, it show added rows.

Here are my activity and my customAdapter :

package com.android.adapter;

import com.android.activity.R;

import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.TextView;

public class NotesCursorAdapter extends CursorAdapter{

    private Context context;
    private static final int TYPE_ITEM = 0;
    private static final int TYPE_ADD_NOTE_BOTTOM = 1;
    private static final int TYPE_ADD_NOTE_TOP = 2;
    private static final int TYPE_MAX_COUNT = TYPE_ADD_NOTE_TOP + 1;

    public NotesCursorAdapter (Context context, Cursor cursor, boolean flag){
        super(context, cursor, flag);
        this.context = context;
    }



    @Override
    public void bindView(View v, Context con, Cursor cursor) {
        TextView content = (TextView)v.findViewById(R.id.note);
        content.setText(cursor.getString(cursor.getColumnIndex("content_note")));
    }

    @Override
    public View newView(Context con, Cursor cursor, ViewGroup vp) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View v = inflater.inflate(R.layout.row_note, vp, false);
        bindView(v, context, cursor);
        return v;

    }

}


package com.android.activity;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

import com.android.adapter.NotesCursorAdapter;
import com.android.database.NoteDataSource;

public class EverydayNotesAndroid3Activity extends Activity {
    /** Called when the activity is first created. */

    private Cursor cursorNotes;
    private NoteDataSource dataNoteConnector;
    private NotesCursorAdapter notesCursorAdapter;
    private Activity activity;
    private ListView listView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        activity = this;

        dataNoteConnector = new NoteDataSource(activity);

        dataNoteConnector.open();

        cursorNotes = dataNoteConnector.getAllNotes();

        startManagingCursor(cursorNotes);

        listView = (ListView) findViewById(R.id.main_list);

        notesCursorAdapter = new NotesCursorAdapter(activity, cursorNotes, true);

        listView.setAdapter(notesCursorAdapter);

        Button b = new Button(activity);

        b = (Button) findViewById(R.id.done);

        b.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                cursorNotes = dataNoteConnector.createNoteTop("American Alex is god");
                cursorNotes.requery();
                System.out.println("and everyone should listen to him");


//              notesCursorAdapter.changeCursor(cursorNotes); // automatically closes old Cursor
//              notesCursorAdapter.notifyDataSetChanged();
            }
        });

}

Thanks for paying attention.

EDIT : I've found a solution but I hate it, I wish there were an other solution.

Now I have in my activity :

cursorNotes = dataNoteConnector.createNoteTop("American Alex is god");

                cursorNotes = dataNoteConnector.getAllNotes();

                notesCursorAdapter = new NotesCursorAdapter(activity, cursorNotes, true);

                listView.setAdapter(notesCursorAdapter);

I find it insane, there should be a simpler way to update the list after an update. Here, I'm recreating a cursor, recreating a cursorAdapter that I feed with the new cursor, an then affect this cursorAdapter to the listView. This is as the notepad example from android doc, but I'm sure there is a way to update the the adapter and the listView just by manipulating the cursor, but I'm not smart enough to figure it out.

Answer 1

try un commenting the last line in your activity

adapter.notifydatasetcanged();

Answer 2

This is what Google has to say about requery()

This method is deprecated. Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back.

You can check it out here. http://developer.android.com/reference/android/database/Cursor.html

So they actually suggest you do what you have done. :) But if you still want to do it the other way, uncomment the notesCursorAdapter.notifyDataSetChanged(). Ideally requery() is supposed to call the noifydatasetchange(), but I have observed that an explicit call is required to refresh the list.

Answer 3

well i won't recommend @Aashish solution. the best thing would be to make you listview and adapter member variables and then recreate adapter

private ListView listView;
private ListAdapter notesCursorAdapter;
private Cursor cursorNotes;

private void update() {
notesCursorAdapter = new NotesCursorAdapter(activity, cursorNotes, true); 
listView.setAdapter(notesCursorAdapter);
}