Bdtjtk

In my App i have a ListView, if i add some new Items, the ListView does not shown the Items. The items will be shown if i close the app and go back in it.

So my new Items are saved in my Database, but the list will not be synchronized.
i followed a Tutorial on youtube, if he tries it, it works fine, but not in my app. i hope someone can help me to find my problem.

In my newItem_Activity i have an Add-Button with following Code:

btnAdd.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                if(todo.getName() == null){

                    Toast.makeText(ToDoCreateNew.this, "Please insert some value.", Toast.LENGTH_LONG).show();

                    return;

                }    

            ToDoDatabaseHelper.getInstance(ToDoCreateNew.this).createTodo(todo);

            finish();

            }

        });

My Database looks like this:

public ToDo createTodo(final ToDo todo) {

        SQLiteDatabase database = this.getWritableDatabase();



        ContentValues contentValues = new ContentValues();

        contentValues.put(NAME_COLUMN, todo.getName());

        contentValues.put(DUEDATE_COLUMN, todo.getDueDate() == null ? null : todo.getDueDate().getTimeInMillis() / 1000);

        contentValues.put(FAVORITE_COLUMN, todo.isFavorite() ? 1 : 0);

        contentValues.put(DESCRIPTION_COLUMN, todo.getDescription());

        contentValues.put(DUETIME_COLUMN, String.valueOf(todo.getDueTime() == null ? null : todo.getDueTime().getTime()));



        long newID = database.insert(TABLE_NAME, null, contentValues);

        database.close();

        return readToDo(newID);

    }



public List<ToDo> readAllToDos(){

    List<ToDo> todos = new ArrayList<>();

    SQLiteDatabase database = this.getReadableDatabase();



    Cursor c = database.rawQuery("SELECT * FROM " + TABLE_NAME, null);

    if (c.moveToFirst()){

        do {

            ToDo todo = readToDo(c.getLong(c.getColumnIndex(ID_COLUMN)));

            if (todo != null){

                todos.add(todo);

            }

        } while (c.moveToNext());



    }

    database.close();

    return todos;

}

and this Code is on my Activity with my ListView:

List<ToDo> dataSource;

ToDoOverviewListAdapter adapter;



protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_to_do_overview);  



    lv = (ListView) findViewById(R.id.listToDo);

    dataSource = ToDoDatabaseHelper.getInstance(this).readAllToDos();



    adapter = new ToDoOverviewListAdapter(this, dataSource);

    lv.setAdapter(new ToDoOverviewListAdapter(this, dataSource));

}



// Go to Activity to Add new Item - Add Button is in newItem_Activity

public void createToDo(){

    startActivity(new Intent(ToDoOverview.this, ToDoCreateNew.class));

    refreshListView();

}   



private void refreshListView(){

    dataSource.clear();

    dataSource.addAll(ToDoDatabaseHelper.getInstance(this).readAllToDos());

    adapter.notifyDataSetChanged();

}

Do one thing when you add lists in adapter , wrap it in a method and call that method in both onCreate and OnStart Method . So basically you have to add list in adapter two times On OnCreate method and OnStart method. So When you update the data and move back to your original activity it will trigger OnStart method and it will show updated data.