private void TaoMoi(object sender, EventArgs e)
{
frmMuaHang muaHang = new frmMuaHang();
muaHang.ShowDialog();
muaHang.MdiParent = this.ParentForm.ParentForm.ParentForm;
}
private void btnMuaHang_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
{
frmMuaHang muaHang = new frmMuaHang();
if (ExistsForm(muaHang))
{
return;
}
muaHang.MdiParent = this;
muaHang.Show();
}