public void LoadInvoices(InvoiceCatalogFilter filter) { using (var db = DB.GetContext()) { var invoices = InvoiceRepository.FindInvoices(db, filter); foreach (var inv in this.ActiveModel) { var find = invoices.Where(i => i.InvoiceID == inv.InvoiceID).FirstOrDefault(); if (find != null) { find.IsMarked = inv.IsMarked; } } this.ActiveModel.Clear(); this.ActiveModel.AddRange(invoices); } }