winform窗体中遍历当前页面全部控件并赋值

麻烦各位高手给看下下面的代码，那里出错了，遍历当前页面全部控件。窗体里面有groupBox以及panel
private void BcforLoading(Control container)
        {
            foreach (Control com in container.Controls)
            {
                if (com.HasChildren)
                {
                    BcforLoading(com);
                }
                if (com.Name.Substring(com.Name.Length – 4, 4) == “_JCZ” && com is ComboBox)
                {
                    ComboBox cb = (ComboBox)com;
                    cb.Items.Add(UserContext.LoggedUser);
                    cb.SelectedItem = UserContext.LoggedUser;
                }
                if (com.Name.Substring(com.Name.Length – 3, 3) == “_BZ” && com is ComboBox)
                {
                    ComboBox cb = (ComboBox)com;
                    cb.SelectedValue = UserContext.LoggedUserTeam;
                }
                if (com.Name.Substring(com.Name.Length – 3, 3) == “_BC” && com is ComboBox)
                {
                    ComboBox cb = (ComboBox)com;
                    cb.SelectedValue = UserContext.LoggedUserSort;
                }
            }
        }