I’ve been writing this for a while today and couldn’t figure out why I couldn’t get the application to create within IIS. The virtual directory created without problems, but after that nothing happened. It turns out that the msdn library was incorrect!

Here is a working IIS 6 virtual directory creator. The only paramaters that need to be changed are in the // Set comment.

// IIS 6 Virtual Directory Builder and Configuration
// http://r-dunn.co.uk/ieatpenguin/computing/software/962/
// Please feel free to use and distribute

// Set variables: Site_Name,Path_to_wwwroot,Virtual_Directory_Name,Path_to_virtual_dir
// Change the port number after "ServerBindings" if you wish to use a different port.

using System;
using System.IO;
using System.DirectoryServices;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Collections;

namespace System_DirectoryServices_DirectoryEntry_ConfigIIS
{
  class Program
  {
    static void Main(string[] args)
    {
        CreateSite("IIS://Localhost/W3SVC", "555", "Site_Name", "Path_to_wwwroot");
        SetSingleProperty("IIS://Localhost/W3SVC/555", "ServerBindings", ":8080:");
        CreateVDir("IIS://Localhost/W3SVC/1/Root", "Virtual_Directory_Name", "Path_to_virtual_dir");
    }

    static void CreateSite(string metabasePath, string siteID, string siteName, string physicalPath)
    {
      //  metabasePath is of the form "IIS://<servername>/<service>"
      //    for example "IIS://localhost/W3SVC" 
      //  siteID is of the form "<number>", for example "555"
      Console.WriteLine("\nCreating site {0}/{1}, mapping the Root application to {2}:", 
          metabasePath, siteID, physicalPath);

      try
      {
        DirectoryEntry service = new DirectoryEntry(metabasePath);
        string className = service.SchemaClassName.ToString();
        if (className.EndsWith("Service"))
        {
          DirectoryEntries sites = service.Children;
          DirectoryEntry newSite = sites.Add(siteID, (className.Replace("Service", "Server")));
          newSite.Properties["ServerComment"][0] = siteName;
          newSite.CommitChanges();

          DirectoryEntry newRoot;
          newRoot = newSite.Children.Add("Root", "IIsWebVirtualDir");
          newRoot.Properties["Path"][0] = physicalPath;
          newRoot.Properties["AccessScript"][0] = true;
          newRoot.CommitChanges();

          Console.WriteLine(" Done. Your site will not start until you set the ServerBindings or SecureBindings property.");
        }
        else
          Console.WriteLine(" Failed. A site can only be created in a service node.");
      }
      catch (Exception ex)
      {
        Console.WriteLine("Failed in CreateSite with the following exception: \n{0}", ex.Message);
      }
    }

    static void SetSingleProperty(string metabasePath, string propertyName, object newValue)
    {
      //  metabasePath is of the form "IIS://<servername>/<path>"
      //    for example "IIS://localhost/W3SVC/1" 
      Console.WriteLine("\nSetting single property at {0}/{1} to {2} ({3}):",
          metabasePath, propertyName, newValue, newValue.GetType().ToString());

      try
      {
          DirectoryEntry path = new DirectoryEntry(metabasePath);
          PropertyValueCollection propValues = path.Properties[propertyName];
          string oldType = propValues.Value.GetType().ToString();
          string newType = newValue.GetType().ToString();
          Console.WriteLine(" Old value of {0} is {1} ({2})", propertyName, propValues.Value, oldType);
          if (newType == oldType)
          {
              path.Properties[propertyName][0] = newValue;
              path.CommitChanges();
              Console.WriteLine("Done");
          }
          else
              Console.WriteLine(" Failed in SetSingleProperty; type of new value does not match property");
      }
      catch (Exception ex)
      {
          if ("HRESULT 0x80005006" == ex.Message)
              Console.WriteLine(" Property {0} does not exist at {1}", propertyName, metabasePath);
          else
              Console.WriteLine("Failed in SetSingleProperty with the following exception: \n{0}", ex.Message);
      }
    }

    static void CreateVDir(string metabasePath, string vDirName, string physicalPath)
    {
      //  metabasePath is of the form "IIS://<servername>/<service>/<siteID>/Root[/<vdir>]"
      //    for example "IIS://localhost/W3SVC/1/Root" 
      Console.WriteLine("\nCreating virtual directory {0}/{1}, mapping the Root application to {2}:",
          metabasePath, vDirName, physicalPath);

      try
      {
        DirectoryEntry site = new DirectoryEntry(metabasePath);
        string className = site.SchemaClassName.ToString();
        if ((className.EndsWith("Server")) || (className.EndsWith("VirtualDir")))
        {
          DirectoryEntries vdirs = site.Children;
          DirectoryEntry newVDir = vdirs.Add(vDirName, (className.Replace("Service", "VirtualDir")));
          newVDir.Properties["Path"][0] = physicalPath;
          newVDir.Properties["AccessScript"][0] = true;

          // Create Application, set appropriate documents and permissions
          newVDir.Invoke("AppCreate", new object[1] { 1 });
          newVDir.Properties["AppFriendlyName"].Value = vDirName;
          newVDir.Properties["EnableDirBrowsing"][0] = false;
          newVDir.Properties["AccessRead"][0] = true;
          newVDir.Properties["AccessExecute"][0] = true;
          newVDir.Properties["AccessWrite"][0] = false;
          newVDir.Properties["EnableDefaultDoc"][0] = true;
          newVDir.Properties["DefaultDoc"][0] = "ReportsIsapi.dll?Login,ReportsIsapi.dll";
          newVDir.Properties["AspEnableParentPaths"][0] = true;
          newVDir.CommitChanges();

          Console.WriteLine(" Done.");
        }
        else
          Console.WriteLine(" Failed. A virtual directory can only be created in a site or virtual directory node.");
      }
      catch (Exception ex)
      {
        Console.WriteLine("Failed in CreateVDir with the following exception: \n{0}", ex.Message);
      }
    }
  }
}

Don’t forget to use a double ‘\\’ in your pathnames to avoid the compiler interpreting them as an escape sequence. I certainly did.