private void treeList1_FocusedNodeChanged(object sender, DevExpress.XtraTreeList.FocusedNodeChangedEventArgs e)
{
   if (e.Node.Tag is CustomFormNodeTag)
   {
      CustomFormNodeTag tag = e.Node.Tag as CustomFormNodeTag;
      this.ShowMyForm(tag.AssemblyFile, tag.FormNamespace); //打开结点对应的窗体
      this.ShowTagData(tag); //显示结点数据
   }
}

/// <summary>
/// 打开结点对应的窗体
/// </summary>
private void ShowMyForm(string dllFile, string formNamespace)
{
   string root = Application.StartupPath; //获取程序运行目录
   Assembly asm;
   
   
   //如未指定DLL文件，则获取当前执行程序EXE的程序集(ExecutingAssembly)
   if (dllFile == "")
     asm = Assembly.GetExecutingAssembly();
   else//跟据DLL文件创建程序集
     asm = Assembly.LoadFile(root + "\\" + dllFile);
   
   //跟据命名空间动态创建窗体对象
   object o = asm.CreateInstance(formNamespace);
   
   //创建对象成功，打开窗体
   if (o != null && o is Form)
   (o as Form).Show();
   else
   MessageBox.Show("DLL文件或命名空间不正确!");
}