private void OnChangeNotesToUserDefinedRequest( INoteSudokuBox notesBox) { if (notesBox == null) { return; } var foundViewModel = FindViewModel( notesBox.Coordinate, notesBox.ParentCoordinate) as NoteSudokuBoxViewModel; if (foundViewModel == null) { return; } var viewModelIndex = mSudokuBoxViewModels.IndexOf(foundViewModel); var newPredefinedViewModel = new UserFilledSudokuBoxViewModel( mModelsFactoryService.GetUserDefinedSudokuBox( notesBox.Coordinate, notesBox.ParentCoordinate, null), mSudokuService); mSudokuBoxViewModels.RemoveAt(viewModelIndex); mSudokuBoxViewModels.Insert(viewModelIndex, newPredefinedViewModel); RefreshValues(); }