Dieses Dokument hat bereits eine 'DocumentElement' Knoten -Ausnahme

Bekomme ich diese Ausnahme, wenn in versuchen, Daten zu konvertieren, Bezug von Daten, setzen von Tabellen zu xml, um ein XmlDataSource angeben, um Dynamische Menü-Steuerung.

Dies ist der Code, der hinter

 DataSet ds = new DataSet();

        SqlCommand cmdmenu = new SqlCommand("select CategoryID,CategoryName from Category ", ConManager.Con());

        SqlCommand com2 = new SqlCommand("select CategoryIDToSub,subcategoryid ,SubCategoryName from CategorySub", ConManager.Con());
        SqlCommand cmd3 = new SqlCommand("select subcategoryid 'SubCategoryID2',Sub2CategoryName from CategorySub2", ConManager.Con());

        SqlDataAdapter menadapter = new SqlDataAdapter(cmdmenu.CommandText, ConManager.Con());
        SqlDataAdapter menadapter2 = new SqlDataAdapter(com2.CommandText, ConManager.Con());
        SqlDataAdapter menadapter3 = new SqlDataAdapter(cmd3.CommandText, ConManager.Con());
        menadapter.Fill(ds, "Menu");

        menadapter.SelectCommand = com2;
        menadapter2.Fill(ds, "SubMenu");
        menadapter3.SelectCommand = cmd3;
        menadapter3.Fill(ds, "SubSubMenu");

        DataColumn colParent =
        ds.Tables["Menu"].Columns["CategoryID"];
        DataColumn colChild =
        ds.Tables["SubMenu"].Columns["CategoryIDToSub"];

        DataRelation relation = new DataRelation("relationName",
        colParent,
        colChild, true);
        DataRelation Relation2 = new DataRelation("relationName2",
        ds.Tables["SubMenu"].Columns["subcategoryid"],
        ds.Tables["SubSubMenu"].Columns["SubCategoryID2"], true);

        relation.Nested = true;
        Relation2.Nested = true;

        ds.Relations.Add(relation);
        ds.Relations.Add(Relation2);

        XmlDataSource.Data = ds.GetXml();

        if (Request.Params["Sel"] != null)
            Page.Controls.Add(new System.Web.UI.LiteralControl("You selected " + Request.Params["Sel"]));

- und dies ist die Xslt-Datei, die Code

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes" encoding="utf-8"/>


  <!-- Replace root node name Menus with MenuItems
       and call MenuListing for its children-->
  <xsl:template match="/Menus">
    <MenuItems>
      <xsl:call-template name="MenuListing" />
    </MenuItems>
  </xsl:template>

  <!-- Allow for recursive child nodeprocessing -->
  <xsl:template name="MenuListing">
    <xsl:apply-templates select="Menu" />
  </xsl:template>

  <xsl:template match="Menu">
    <MenuItem>
      <!-- Convert Menu child elements to MenuItem attributes -->
      <xsl:attribute name="Text">
        <xsl:value-of select="CategoryName"/>
      </xsl:attribute>
      <xsl:attribute name="ToolTip">
        <xsl:value-of select="Remarks"/>
      </xsl:attribute>
      <xsl:attribute name="NavigateUrl">
        <xsl:text>?Sel=</xsl:text>
        <xsl:value-of select="Text"/>
      </xsl:attribute>
      <xsl:attribute name="Text2">
        <xsl:value-of select="SubCategoryName"/>
      </xsl:attribute>
      <xsl:attribute name="Test3">
        <xsl:value-of select="Sub2CategoryName3"/>
      </xsl:attribute>
      <!-- Recursively call MenuListing forchild menu nodes -->
      <xsl:if test="count(Menu) >0">
        <xsl:call-template name="MenuListing" />
      </xsl:if>
    </MenuItem>
  </xsl:template>
</xsl:stylesheet>

- und das ist die Menü-Steuerung und das XmlDataSource-Code

<asp:Menu ID="Menu" runat="server" BackColor="#E3EAEB"   DynamicHorizontalOffset="2" Font-Names="Verdana" Font-Size="0.8em" ForeColor="#666666" StaticSubMenuIndent="10px" DataSourceID="XmlDataSource" Width="225px" onmenuitemclick="Menu_MenuItemClick">

<DataBindings>
<asp:MenuItemBinding DataMember="MenuItem" NavigateUrlField="NavigateUrl" TextField="Text" />
<asp:MenuItemBinding DataMember="MenuItem" NavigateUrlField="NavigateUrl" TextField="Text2" />
<asp:MenuItemBinding DataMember="MenuItem" NavigateUrlField="NavigateUrl" TextField="Text3" />
</DataBindings>

            <StaticSelectedStyle BackColor="#1C5E55" />
            <StaticMenuItemStyle HorizontalPadding="5px" VerticalPadding="2px" />
            <DynamicHoverStyle BackColor="#666666" ForeColor="White" />
            <DynamicMenuStyle BackColor="#E3EAEB" />
            <DynamicSelectedStyle BackColor="#1C5E55" />
            <DynamicMenuItemStyle HorizontalPadding="5px" VerticalPadding="2px" />
            <StaticHoverStyle BackColor="#666666" ForeColor="White" />
      </asp:Menu>                       
      <asp:XmlDataSource ID="XmlDataSource" runat="server"
            TransformFile="~/TransformXSLT.xsl" XPath="MenuItems/MenuItem">
      </asp:XmlDataSource>