private void btn_group_Click(object sender, RoutedEventArgs e)
        {
            if (allowAction)
            {
                List<ContactDB> listCheckedContact = GetCheckedContactList();
                Window_BelongToGroup frm = new Window_BelongToGroup(this, listCheckedContact);
                frm.ShowDialog();

                int count = listview_contacts.Items.Count;
                for (int i = 0; i < count; i++)
                {
                    Object item = listview_contacts.Items[i];
                    if (item is ListViewContactItem)
                    {
                        if (((ListViewContactItem)item).IsCheck)
                        {
                            return;
                        }
                    }
                }

                btn_delete.IsEnabled = false;
                btn_group.IsEnabled = false;
            }
        }
 private void btn_group_Click(object sender, RoutedEventArgs e)
 {
     if (allowAction)
     {
         List<Object> list = GetCheckedContactList();
         Window_BelongToGroup frm = new Window_BelongToGroup(this, list, uc_AddressBook.ListGroupName);
         frm.ShowDialog();
     }
 }