This article illustrates how to populate a Treeview control from an XML file in Visual Basic.

Step by Step Example

Note The sample code provided in this article contains a reference to MSXML 2.0.

If a newer version of MSXML has been installed in side-by-side mode, you must explicitly use the Globally Unique Identifiers (GUIDs) or ProgIDs for that version to run the sample code. For example, MSXML version 4.0 can only be installed in side-by-side mode. For additional information about the code changes that are required to run the sample code with the MSXML 4.0 parser, click the following article number to view the article in the Microsoft Knowledge Base: If a newer version of MSXML has been installed in side-by-side mode on your machine, the code may use the older version.

1. Paste following XML code into an empty text file and save the file as Sample.xml:

   <?xml version="1.0"?>
      <family>
      <parent>id="grandfather"
          <parent>id="father"
               <parent>id="brother"
                  <child>id="niece"
                  </child>
               </parent>
               <parent>id="me"
                  <child>id="son"</child>
                  <child>id="daughter"</child>
               </parent>
               <child>id="sister"</child>
           </parent>
           <parent>id="uncle"
               <parent>id="cousin sister"
                  <child>id="second cousin"</child>
               </parent>
               <child>id="cousin brother"</child>
           </parent>
      </parent>
      </family>
   					

2. Create a Standard EXE project in Visual Basic. Form1 is added by default.
3. From the Project menu, choose References, and add a reference to Microsoft XML, version 2.0.
4. From the Project menu, choose Components, and add the Microsoft Windows Common Controls to the project.
5. Add a command button, a text box, a label, and a Treeview control to the form.
6. Paste the following code into Form1:

      Option Explicit
      Dim XMLDoc As MSXML.DOMDocument
   
      'To use a newer version of MSXML parser, use a declaration like the   
      'following with the appropriate version in the ProgID. Same applies to the 
      'other sections of the code:
      'Dim XMLDoc As MSXML2.DOMDocument40
   
   Private Sub Form_Load()
       Form1.Move 0, 0, 5565, 4495
       Command1.Move 120, 600, 1335, 375
       Text1.Move 1560, 120, 3735, 285
       Label1.Move 120, 120, 1575, 285
       TreeView1.Move 120, 1080, 5175, 2895
       Command1.Caption = "Load XML File"
       Label1.Caption = "Enter path:"
       Text1.Text = App.Path & "\Sample.XML"
       Form1.Caption = "Load XML File Sample"
   End Sub
   
   Private Sub Command1_Click()
       Set XMLDoc = New DOMDocument
       XMLDoc.async = False
       'XMLDoc.validateOnParse = False
       'If validation is not important, skip it
       XMLDoc.Load Text1.Text
       
       If XMLDoc.parseError.errorCode = 0 Then
           MsgBox "Succeeded"
           If XMLDoc.readyState = 4 Then
               TreeView1.Nodes.Clear
               AddNode XMLDoc.documentElement
           End If
       Else
           MsgBox XMLDoc.parseError.reason & vbCrLf & _
           XMLDoc.parseError.Line & vbCrLf & _
           XMLDoc.parseError.srcText
       End If
       
   End Sub
   
   Private Sub AddNode(ByRef XML_Node As IXMLDOMNode, _
                       Optional ByRef TreeNode As Node)
       Dim xNode As Node
       Dim xNodeList As IXMLDOMNodeList
       Dim i As Long
       
       If TreeNode Is Nothing Then
           Set xNode = TreeView1.Nodes.Add
       Else
           Set xNode = TreeView1.Nodes.Add(TreeNode, tvwChild)
       End If
       
       xNode.Expanded = True
       xNode.Text = XML_Node.nodeName
       
       If xNode.Text = "#text" Then
           xNode.Text = XML_Node.nodeTypedValue
       Else
           xNode.Text = "<" + xNode.Text + ">"
       End If
       
       Set xNodeList = XML_Node.childNodes
       For i = 0 To xNodeList.length - 1
           AddNode xNodeList.Item(i), xNode
       Next
   End Sub
   					

7. Run the project.
8. Type the path to Sample.xml, and then click the command button.