private void btnDelete_Click(object sender, EventArgs e) { object objId = gvLines.GetFocusedRow(); if (objId == null) { return; } int cardViewId = (objId as CardView).Id; int cardPermissionId = cardPermissions.Where(x => x.CardId == cardViewId).FirstOrDefault().Id; Operation <string> operation = OperationHandler.DeleteObjectById(nameof(CardPermission), cardPermissionId); if (!operation.Successful) { MessageBox.Show(operation.Fail); } refreshLines(); }