private void bbiRefresh_ItemClick(object sender, ItemClickEventArgs e)
{
QLHD hd = new QLHD();
hd.Show();
this.Hide();
}
private void barButtonItem1_ItemClick(object sender, ItemClickEventArgs e)
{
QLHD hd = new QLHD();
this.Hide();
hd.Show();
}