Finding a Particular Node in an XML Document (VB)

<%@ Page language="vb" AutoEventWireup="true" %>
<%@ Import Namespace="System.Data" %>
<script language="vb" runat="server">

Protected xmlSource As New System.Xml.XmlDocument()
    
Private Sub LoadButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) 
    Dim xmlDocStream As System.IO.Stream = GetXmlDoc(XmlSourceTextBox.Text)
    If Not (xmlDocStream Is Nothing) Then
    xmlSource.Load(xmlDocStream)
    ResultText.Text = xmlSource.InnerXml
    Else
    ResultText.Text = "Could not resolve the XML document."
    End If
End Sub

Public Shared Function GetXmlDoc(ByVal xmlsource As String) As System.IO.Stream
    Dim stream As System.IO.Stream = Nothing
    If xmlsource.StartsWith("<?xml") Or xmlsource.StartsWith("<schema") Then
    stream = New System.IO.MemoryStream(System.Text.ASCIIEncoding.ASCII.GetBytes(xmlsource))
    Else
    Try
      Dim xmluri As New System.Uri(xmlsource)
      If xmluri.IsFile Then
          stream = New System.IO.FileStream(xmlsource, System.IO.FileMode.Open)
      Else
          Dim request As System.Net.HttpWebRequest = CType(System.Net.WebRequest.Create(xmluri), System.Net.HttpWebRequest)
          Dim response As System.Net.WebResponse = request.GetResponse()
          stream = response.GetResponseStream()
      End If
    Catch e As Exception
    End Try 'not a valid uri
    End If
    Return stream
End Function

Private Sub QueryButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) 
    Dim s as new System.Text.StringBuilder()
    
    If xmlSource Is Nothing Or xmlSource.InnerText = "" Then
    xmlSource.LoadXml(ResultText.Text)
    End If
    Try
    Dim nl As System.Xml.XmlNodeList = xmlSource.SelectNodes(XPathText.Text)
    Dim counter As Integer = 1
    Dim node As System.Xml.XmlNode
    For Each node In nl
      s.Append(Convert.ToString(counter) + "]" + node.InnerText + System.Environment.NewLine)
          
      counter += 1
    Next node
    QueryResult.Text=s.ToString()
    Catch selectNodesError As Exception
      QueryResult.Text = selectNodesError.ToString()
    End Try
End Sub
</script>
<HTML>
  <HEAD>
    <title>Finding a Particular Node in an XML Document</title>
  </HEAD>
  <body>
    <form id="Form1" method="post" runat="server">
      <asp:textbox id="XmlSourceTextBox" runat="server" Width="379px" Height="162px" TextMode="MultiLine"></asp:textbox><br/>
      <asp:button id="LoadButton" runat="server" Text="Load XML Document" OnClick="LoadButton_Click"></asp:button><br/>
      <asp:TextBox id="ResultText" runat="server" Width="379px" Height="194px" TextMode="MultiLine"></asp:TextBox><br/>
      <asp:Button id="QueryButton" runat="server" Text="Query" OnClick="QueryButton_Click"></asp:Button><br/>
      <asp:TextBox id="XPathText" runat="server" Width="379px"></asp:TextBox><br/>
      <asp:TextBox id="QueryResult" runat="server" TextMode="MultiLine" Height="229px" Width="379"></asp:TextBox>
    </form>
  </body>
</HTML>

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5.	Finding a Particular Node in an XML Document?
6.	Using the XPathNavigator for Navigating Xml Documents

Finding a Particular Node in an XML Document (VB) : XPath « XML « ASP.Net

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