private async void InsertItemAsync() { var title = TBAddItemTitle.Text; var description = TBAddItemDescription.Text; var author = TBAddItemAuthor.Text; var response = new AuthResponseModel(); int publishYear; if (!Regex.IsMatch(TBAddItemPublishYear.Text, @"^\d{4}$")) { MessageBox.Show("Year should consist of 4 Numbers!"); return; } else { publishYear = Convert.ToInt32(TBAddItemPublishYear.Text); } ComboBoxItem typeItem = (ComboBoxItem)CBAddItemCategory.SelectedItem; string category = typeItem.Content.ToString(); ComboBoxItem typeItem2 = (ComboBoxItem)CBAddItemAccess.SelectedItem; string access = typeItem2.Content.ToString(); if (category == T13.Content.ToString()) //Books { BookProcessor book = new BookProcessor(); response = await book.InsertBook(title, description, author, publishYear, access); MessageBox.Show(response.Info); } else if (category == T14.Content.ToString()) //Newspapers { NewspaperProcessor newspaper = new NewspaperProcessor(); response = await newspaper.InsertNewspaper(title, description, author, publishYear, access); MessageBox.Show(response.Info); } else if (category == T15.Content.ToString()) //Journals { JournalProcessor journal = new JournalProcessor(); response = await journal.InsertJournal(title, description, author, publishYear, access); MessageBox.Show(response.Info); } else if (category == T16.Content.ToString()) //Magazines { MagazineProcessor magazine = new MagazineProcessor(); response = await magazine.InsertMagazine(title, description, author, publishYear, access); MessageBox.Show(response.Info); } else if (category == T17.Content.ToString()) //Manuscripts { ManuscriptProcessor manuscript = new ManuscriptProcessor(); response = await manuscript.InsertManuscript(title, description, author, publishYear, access); MessageBox.Show(response.Info); } }