Save an ASP.NET TreeView Control to an XML File

Here are two methods to help you take a TreeView web control and save / export / serialize it to a file. Add these two statements to the top of the file:

using System.Xml;
using System.Text;

These two methods take the TreeView and recursively loop through all the TreeNode controls.

/// <summary>
/// Recurses through a TreeView web control exports the results
/// to an XML file nested to match the TreeView. Properties are
/// saved as attributes when a value is set.
/// <summary>
/// <param name="myTreeView">A TreeView web control.</param>
/// <param name="myFile">A file path and name with extension.</param>
protected void TreeViewToXml(System.Web.UI.WebControls.TreeView 
    myTreeView, string myFile)
{
 try
 {
  XmlTextWriter xmlWriter = new XmlTextWriter(myFile, Encoding.UTF8);
  xmlWriter.Formatting = Formatting.Indented;
  xmlWriter.Indentation = 3;
  xmlWriter.WriteStartDocument();
  // Opens <TreeView>, the root node.
  xmlWriter.WriteStartElement("TreeView"); 
  
  // Go through child nodes.
  ProcessNodes(myTreeView.Nodes, xmlWriter);           

  // </TreeView>, the root node.
  xmlWriter.WriteEndElement();  
  xmlWriter.WriteEndDocument();

  // Closes the object and saves the document to disk.
  xmlWriter.Close(); 
 }
 catch
 {
  throw; // Throw any exceptions up the line.
 }
}

/// <summary>
/// Recursively processes each TreeNode within a TreeNodeCollection
/// from a TreeView web control.
/// </summary>
/// <param name="myTreeNodes">A TreeNodeCollection from a TreeView web
/// control.</param>
/// <param name="myWriter">A XmlTextWriter being used to hold the XML
/// results from the TreeViewToXml method.</param>
protected void ProcessNodes(TreeNodeCollection myTreeNodes, 
    XmlTextWriter myWriter)
{
 foreach (TreeNode thisNode in myTreeNodes)
 {
  myWriter.WriteStartElement("TreeNode"); // <TreeNode>.
  
  // Go through each property and set it as an attribute if it exists.
  if(!String.IsNullOrEmpty(thisNode.Text))
   myWriter.WriteAttributeString("Text", thisNode.Text);
  if (!String.IsNullOrEmpty(thisNode.ImageToolTip))
   myWriter.WriteAttributeString("ImageToolTip", 
     thisNode.ImageToolTip);
  if (!String.IsNullOrEmpty(thisNode.ImageUrl))
   myWriter.WriteAttributeString("ImageUrl", thisNode.ImageUrl);
  if (!String.IsNullOrEmpty(thisNode.NavigateUrl))
   myWriter.WriteAttributeString("NavigateUrl", 
      thisNode.NavigateUrl);
  if (!String.IsNullOrEmpty(thisNode.SelectAction.ToString()))
   myWriter.WriteAttributeString("SelectAction", 
      thisNode.SelectAction.ToString());
  if (!String.IsNullOrEmpty(thisNode.Target)) 
   myWriter.WriteAttributeString("Target", thisNode.Target);
  if (!String.IsNullOrEmpty(thisNode.ToolTip))
   myWriter.WriteAttributeString("ToolTip", thisNode.ToolTip);
  if (!String.IsNullOrEmpty(thisNode.Value))
   myWriter.WriteAttributeString("Value", thisNode.Value);
  if (!String.IsNullOrEmpty(thisNode.ValuePath))
   myWriter.WriteAttributeString("ValuePath", thisNode.ValuePath);
  if (thisNode.ShowCheckBox.HasValue)
   myWriter.WriteAttributeString("ShowCheckBox", 
      thisNode.ShowCheckBox.ToString());
  if (thisNode.Expanded.HasValue)
   myWriter.WriteAttributeString("Expanded", 
      thisNode.Expanded.ToString());
  myWriter.WriteAttributeString("Selected", 
    thisNode.Selected.ToString());
  myWriter.WriteAttributeString("Checked", 
    thisNode.Checked.ToString());
            
  // Recurse through any child nodes.
  if (thisNode.ChildNodes.Count > 0) 
    ProcessNodes(thisNode.ChildNodes, myWriter);

  myWriter.WriteEndElement(); // </TreeNode>.
 }
}