private void ClbChuDe_SelectedIndexChanged(object sender, EventArgs e)
{
string a = "";
if (clbChuDe.CheckedItems.Count > 0)
{
for (int i = 0; i < clbChuDe.CheckedItems.Count; i++)
{
a = (clbChuDe as ListBox).GetItemText((clbChuDe as ListBox).SelectedItem);
}
dgvSanPham.DataSource = db.Sachtheochude(a);
}
else
{
dgvSanPham.DataSource = db.InfoSach();
}
}