private void CustomerListForm_Load(object sender, EventArgs e) { // fetch data async CustomerList.BeginGetReadOnlyList(string.Empty, (o, ev) => { if (ev.Error != null) { MessageBox.Show(this, ev.Error.Message, "Error loading data", MessageBoxButtons.OKCancel); } else { customerListBindingSource.Rebind(ev.Object); } }); }