XmlDataSource.GetXmlDocument Method

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Loads the XML data into memory, either directly from the underlying data storage or from the cache, and returns it in the form of an XmlDataDocument object.

public:
 System::Xml::XmlDocument ^ GetXmlDocument();

public System.Xml.XmlDocument GetXmlDocument ();

member this.GetXmlDocument : unit -> System.Xml.XmlDocument

Public Function GetXmlDocument () As XmlDocument

Returns

XmlDocument

An XmlDataDocument object that represents the XML specified in the Data property or in the file identified by the DataFile property, with any transformations and XPath queries applied.

Exceptions

InvalidOperationException

A URL is specified for the DataFile property; however, the XmlDataSource control does not have the correct permissions for the Web resource.

NotSupportedException

A URL is specified for the DataFile property; however, it is not an HTTP-based URL.

-or-

A design-time relative path was not mapped correctly by the designer before using the XmlDataSource control.

-or-

Both caching and client impersonation are enabled. The XmlDataSource control does not support caching when client impersonation is enabled.

HttpException

Access is denied to the path specified for the DataFile property.

Examples

This section contains two code examples. The first example demonstrates how to use an XmlDataSource control with a TreeView control to display and edit XML data contained in an XML file. The second example demonstrates how to use an XmlDataSource control with a templated Repeater control to display and edit XML data contained in an XML file.

The following code example demonstrates how to use an XmlDataSource control with a TreeView control to display and edit XML data contained in an XML file. The data is manipulated in memory using the GetXmlDocument method every time you select a TreeView node, and is then saved to the XML file. Finally, DataBind is called on the TreeView control to refresh the data that it displays.

<%@ Page LANGUAGE="C#" SMARTNAVIGATION="false" %>
<%@ Import Namespace="System.Xml" %>

<script runat="server" >
  void TreeView1_SelectedNodeChanged(Object sender, EventArgs e)
  {
    XmlDocument myXml = new XmlDocument();
    myXml=(XmlDocument)XmlSource.GetXmlDocument();

    String iterator = TreeView1.SelectedNode.DataPath;

    XmlNode myNode = myXml.SelectSingleNode(iterator);

    myNode.InnerText = "ThisIsATest";
    XmlSource.Save();
    TreeView1.DataBind();
    TreeView1.ExpandAll();
  }
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="Form1" runat="server">

      <asp:xmldatasource
        runat="server"
        id="XmlSource"
        xpath="/bookstore/book"
        datafile="Booksort.xml"
        enableviewstate="False"
        enablecaching="False" />

      <asp:treeview
        runat="server"
        id="TreeView1"
        ExpandDepth="3"
        datasourceid="XmlSource"
        maxdatabinddepth="3"
        autogeneratedatabindings="False"
        onselectednodechanged="TreeView1_SelectedNodeChanged" >
        <databindings>
          <asp:treenodebinding datamember="book" valuefield="publicationdate" />
          <asp:treenodebinding datamember="title" valuefield="#InnerText" />
          <asp:treenodebinding datamember="author" valuefield="#InnerText" />
          <asp:treenodebinding datamember="first-name" valuefield="#InnerText" />
          <asp:treenodebinding datamember="last-name" valuefield="#InnerText" />
        </databindings>
      </asp:treeview>
    </form>
  </body>
</html>

<%@ Page LANGUAGE="VB" SMARTNAVIGATION="false" %>
<%@ Import Namespace="System.Xml" %>

<script runat="server" >
  Private Sub TreeView1_SelectedNodeChanged(sender As Object, e As EventArgs)

    Dim myXml As New XmlDocument
    myXml = CType(XmlSource.GetXmlDocument(), XmlDataDocument)

    Dim iterator As String = TreeView1.SelectedNode.DataPath
    Dim myNode As XmlNode = myXml.SelectSingleNode(iterator)

    myNode.InnerText = "ThisIsATest"
    XmlSource.Save()
    TreeView1.DataBind()
    TreeView1.ExpandAll()
  End Sub ' TreeView1_SelectedNodeChanged
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="Form1" runat="server">

      <asp:xmldatasource
        runat="server"
        id="XmlSource"
        xpath="/bookstore/book"
        datafile="Booksort.xml"
        enableviewstate="False"
        enablecaching="False" />

      <asp:treeview
        runat="server"
        id="TreeView1"
        ExpandDepth="3"
        datasourceid="XmlSource"
        maxdatabinddepth="3"
        autogeneratedatabindings="False"
        onselectednodechanged="TreeView1_SelectedNodeChanged" >
        <databindings>
          <asp:treenodebinding datamember="book" valuefield="publicationdate" />
          <asp:treenodebinding datamember="title" valuefield="#InnerText" />
          <asp:treenodebinding datamember="author" valuefield="#InnerText" />
          <asp:treenodebinding datamember="first-name" valuefield="#InnerText" />
          <asp:treenodebinding datamember="last-name" valuefield="#InnerText" />
        </databindings>
      </asp:treeview>
    </form>
  </body>
</html>

The following code example demonstrates how to use an XmlDataSource control with a templated Repeater control to display and edit XML data contained in an XML file. As with the previous example, the data is manipulated in memory using the XmlDataDocument retrieved by the GetXmlDocument method. Finally, DataBind is called on the TreeView control to refresh the data that it displays.

<%@ Page LANGUAGE="C#" SMARTNAVIGATION="false" %>
<%@ Import NameSpace="System.Xml" %>
<script runat="server" >

  void Button1_Click(Object sender, EventArgs e)
  {
    XmlDocument myXml = new XmlDocument();
    myXml=(XmlDocument)XmlSource.GetXmlDocument();

    String path = "bookstore/book/@publicationdate";
    XmlNodeList nodeList;
    nodeList = myXml.SelectNodes(path);
    foreach (XmlNode date in nodeList)
      {
        int helper = int.Parse(date.Value) + 2;
        date.Value = helper.ToString();
      }
    XmlSource.Save();
    Repeater1.DataBind();
  }

</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="Form1" runat="server" >

      <asp:XmlDataSource
        runat="server"
        ID="XmlSource"
        XPath="bookstore/book[@genre='novel']"
        DataFile="Booksort2.xml"
        EnableViewState="True"
        EnableCaching="False" />

      <asp:Repeater
        runat="server"
        ID="Repeater1"
        DataSourceID="XmlSource" >
          <ItemTemplate >
            <h1><%# XPath ("title/text()") %> </h1>
              <b>Author:</b><%# XPath ("author/first-name/text()") %> <%# XPath ("author/last-name/text()") %>
              <b>PublicationDate:</b><%# XPath ("@publicationdate") %>
              <b>Price:</b><%# XPath ("price/text()") %>
          </ItemTemplate>
      </asp:Repeater>


      <p><asp:Button
        runat="server"
        ID="Button1"
        onclick="Button1_Click"
        Text="Add 2 years to the Publication Date!" /></p>
</form>
</body>
</html>

<%@ Page LANGUAGE="VB" SMARTNAVIGATION="false" %>
<%@ Import Namespace="System.Xml" %>

<script runat="server" >

  Private Sub Button1_Click(sender As Object, e As EventArgs)

    Dim myXml As New XmlDocument
    myXml = CType(XmlSource.GetXmlDocument(), XmlDocument)

    Dim path As String = "bookstore/book/@publicationdate"
    Dim nodeList As XmlNodeList = myXml.SelectNodes(path)

    Dim aDate As XmlNode
    For Each aDate In  nodeList
      Dim helper As Integer = Int32.Parse(aDate.Value) + 2
      aDate.Value = helper.ToString()
    Next aDate

    XmlSource.Save()
    Repeater1.DataBind()

  End Sub 'Button1_Click
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="Form1" runat="server" >

      <asp:XmlDataSource
        runat="server"
        ID="XmlSource"
        XPath="bookstore/book[@genre='novel']"
        DataFile="Booksort2.xml"
        EnableViewState="True"
        EnableCaching="False" />

      <asp:Repeater
        runat="server"
        ID="Repeater1"
        DataSourceID="XmlSource" >
          <ItemTemplate >
            <h1><%# XPath ("title/text()") %> </h1>
              <b>Author:</b><%# XPath ("author/first-name/text()") %> <%# XPath ("author/last-name/text()") %>
              <b>PublicationDate:</b><%# XPath ("@publicationdate") %>
              <b>Price:</b><%# XPath ("price/text()") %>
          </ItemTemplate>
      </asp:Repeater>


      <p><asp:Button
        runat="server"
        ID="Button1"
        onclick="Button1_Click"
        Text="Add 2 years to the Publication Date!" /></p>
</form>
</body>
</html>

The XML file in the code examples has the following data:

<?xml version="1.0" encoding="utf-8"?>  
 <bookstore xmlns:bk="urn:samples">  
   <book genre="novel" publicationdate="1999" bk:ISBN="0000000000">  
     <title>Secrets of Silicon Valley</title>  
     <author>  
       <first-name>Sheryl</first-name>  
       <last-name>Hunter</last-name>  
     </author>  
     <price>24.95</price>"   
     </book>  
   <book genre="novel" publicationdate="1985" bk:ISBN="1111111111">  
     <title>Straight Talk About Computers</title>  
     <author>  
       <first-name>Dean</first-name>  
       <last-name>Straight</last-name>  
     </author>  
     <price>29.95</price>  
   </book>  
</bookstore>

Remarks

Use the GetXmlDocument method for direct access to an in-memory representation of the underlying XML data.

You can manipulate the returned XmlDataDocument object and then call Save to persist your changes to the XML file specified by the DataFile property. Several requirements must be met before the XmlDataDocument object can be saved successfully. For more information, see the Save method.

Applies to