ListView updates the entry only when the application is restarted again

Question

In this application, I have a listview and a sqlitedatabase. There is a floating action button which on clicking displays a dialog box containing two edittext one for name and another for number. The problem is that the after clicking on the add option of the dialog box the entry is not shown on the listview. But when the activity is destroyed and onCreate is called again on the activity , the entry is shown.

I tried using adapter.notifyDataSetChanged() but it doesn't work. The code is shown below :

Code

public class DetailsActivity extends AppCompatActivity {

private DatabaseManager manager;
private ListView listView;
private SimpleCursorAdapter adapter;

final String[] from=new String[] {UserDatabase.NAME,UserDatabase.NUMBER};

final int[] to=new int[] {R.id.nameDisplay,R.id.phoneDisplay};


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_details);

    manager = new DatabaseManager(getApplicationContext());
    manager.open();
    Cursor cursor=manager.fetch();

    listView = (ListView) findViewById(R.id.listViewId);
    listView.setEmptyView(findViewById(R.id.empty));

    adapter = new SimpleCursorAdapter(getApplicationContext(),
            R.layout.row_item, cursor, from, to, 0);
    adapter.notifyDataSetChanged();

    listView.setAdapter(adapter);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(DetailsActivity.this);
            LayoutInflater inflater = DetailsActivity.this.getLayoutInflater();
            final View dialogView = inflater.inflate(R.layout.custom_dialog, null);
            dialogBuilder.setView(dialogView);
            final EditText name = (EditText) dialogView.findViewById(R.id.dialogEditNmID);
            final EditText phone = (EditText) dialogView.findViewById(R.id.dialogEditPhID);

            dialogBuilder.setTitle("Add Details");
            dialogBuilder.setPositiveButton("Add", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    if (!TextUtils.isEmpty(name.getText().toString()) &&
                            !TextUtils.isEmpty(phone.getText().toString())) {
                        /*adapter.notifyDataSetChanged();
                        manager.insert(name.getText().toString(), phone.getText().toString());
                        Toast.makeText(getApplicationContext(),
                                "Added " + name.getText().toString(), Toast.LENGTH_SHORT).show();*/
                        insertData(name.getText().toString(),phone.getText().toString());
                    } else {
                        Toast.makeText(getApplicationContext(),
                                "Empty field(s)", Toast.LENGTH_SHORT).show();
                    }

                }
            });

            dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });

            AlertDialog b = dialogBuilder.create();
            b.show();
            //  listView.setAdapter(adapter);
            //adapter.notifyDataSetChanged();
        }
    });
}

public void insertData(String fname,String phnumber){
    manager.insert(fname,phnumber);
    listView.setAdapter(adapter);
    adapter.notifyDataSetChanged();
}
}

Some of the statements are commented because I tried to get the desired result but couldn't get it.

Answer 1

After you insert the entries in your database, you should fetch the data again so that your list has the newest entry. So you can either modify your code to be able to add a data point to the list you are passing to the adapter or refetch the data from the database after insertions and before notifyDatasetChanged().