private void BtnDelCat_Click(object sender, EventArgs e) { if (selectedCat != null) { using (var db = new CategoryManager()) { db.DeleteItem(selectedCat); } using (var db = new ExpenseManager()) { var expenses = db.GetItemsByCategory(selectedCat); foreach (var exp in expenses) { exp.CategoryId = 2; db.SaveItem(exp); } } Dialog.Dismiss(); } }