using System.Xml;
using System.IO;

private void AddXmlNode(TreeNodeCollection ATreeNodes, XmlNode AXmlNode)
{
    string BMBH = string.Empty;
    string BMMC = string.Empty;
    string BMLX = string.Empty;
    XmlNode vXmlNode = AXmlNode.SelectSingleNode("BMBH");
    if (vXmlNode != null) BMBH = vXmlNode.InnerText;
    vXmlNode = AXmlNode.SelectSingleNode("BMMC");
    if (vXmlNode != null) BMMC = vXmlNode.InnerText;
    vXmlNode = AXmlNode.SelectSingleNode("BMBH");
    if (vXmlNode != null) BMLX = vXmlNode.InnerText;
    TreeNode vTreeNode = ATreeNodes.Add(BMBH, BMMC);
    vTreeNode.Tag = BMLX;
    foreach (XmlNode vTemp in AXmlNode.SelectNodes("BM"))
    {
        AddXmlNode(vTreeNode.Nodes, vTemp);
    }
}

private void XmlToTree(string AFileName, TreeView ATreeView)
{
    if (ATreeView == null) return;
    if (!File.Exists(AFileName)) return; // 文件不存在
    XmlDocument vXmlDocument = new XmlDocument();
    vXmlDocument.Load(AFileName);
    XmlElement vRoot = vXmlDocument.DocumentElement;
    foreach (XmlNode vXmlNode in vRoot.ChildNodes)
    {
        AddXmlNode(treeView1.Nodes, vXmlNode);
    }
}

private void button1_Click(object sender, EventArgs e)
{
    XmlToTree(@"c:\temp\temp.xml", treeView1);    
}