private void AddTodo_Click(object sender, RoutedEventArgs e) { //set default values to be added to todo collection int userIDToPass = 1; var lastTodo = Todos.Last(); int lastTodoId = lastTodo.id += 1; bool newCompleted = false; string titleCreated = AddNewTodoField.Text; var newTodo = new Todo() { userId = userIDToPass, id = lastTodoId, title = titleCreated, completed = newCompleted }; //add to list of todos at the beginning of the list Todos.Insert(0, newTodo); //show new todo in details view SelectedTodo.Clear(); SelectedTodo.Add(newTodo); //clear searhc field AddNewTodoField.Text = ""; }