ASP.Net Hide Child Nested GridView in MultiLevel Nested GridView if no data or empty

Ref: Nested GridView with TreeView like structure in ASP.Net using C# and VB.Net

Download add the following event on Orders Gridview:

                        <asp:GridView ID="gvOrders" runat="server" AutoGenerateColumns="false" PageSize="5"
                            AllowPaging="true" OnPageIndexChanging="OnOrdersGrid_PageIndexChanging" OnRowDataBound="gvOrders_RowDataBound" CssClass="ChildGrid"
                            DataKeyNames="OrderId">

Here is the C# code of RowDataBound:

protected void gvOrders_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            string orderId = e.Row.Cells[1].Text;
            DataTable dt = GetData(string.Format("SELECT ProductId, ProductName FROM Products WHERE ProductId IN (SELECT ProductId FROM [Order Details] WHERE OrderId = '{0}')", orderId));
            if (dt.Rows.Count < 0)
            {
                ((ImageButton)e.Row.Cells[1].FindControl("imgProductsShow")).Visible = false;
            }
            else
            {
                ((ImageButton)e.Row.Cells[1].FindControl("imgProductsShow")).Visible = true;
            }
        }
    }

it might be possible that the image will not hide tri to debug the code and set the NextStatement As