public void SearchFaculty(object parameter) { IEnumerable <Faculty> faculty = null; IFaculty facultyObj = new FacultyService(new Data.WpfDbContext()); if (Filter == Filter.ById) { if (int.TryParse(FilterParameter, out int res)) { faculty = facultyObj.GetDetailsById(res); } } else if (Filter == Filter.ByName) { faculty = facultyObj.GetDetailsByName(FilterParameter); } FilterFaculty = new ObservableCollection <Faculty>(faculty); }