private void gv_Books_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex > -1 && e.RowIndex > -1)
{
var cell = gv_Books.CurrentCell;
var quantity = Convert.ToInt64(gv_Books.Rows[e.RowIndex].Cells[gv_Books_clm_CartQuantity.Name].Value.ToString());
var cartQuantity = cell.Value?.ToString();
var result = _bookValidator.ValidateQuantity(quantity, cartQuantity);
if (!result.State)
{
cell.ErrorText = result.Result;
cell.Value = "0";
}
else
{
cell.ErrorText = "";
}
}
}