<hr color="#000000"><br>Hello, word ! DTE

using System;
using EnvDTE;

namespace CodeDom
{
 class Class1
 {
   static EnvDTE.Solution sol;
   static EnvDTE.DTE dte;

  [STAThread]
  static void Main(string[] args)
  {   
   dte = (EnvDTE.DTE)  System.Runtime.InteropServices.Marshal.GetActiveObject("VisualStudio.DTE.7.1");
   sol = dte.Solution;
   CodeDomDemo1();
  }

  static void CodeDomDemo1()
  {
   foreach( EnvDTE.Project pro in sol.Projects)
    foreach( EnvDTE.ProjectItem item in pro.ProjectItems)
    {
     foreach( EnvDTE.CodeElement elm in item.FileCodeModel.CodeElements )
     {
      if( elm.Kind   == vsCMElement.vsCMElementNamespace )
      {
       EnvDTE.CodeNamespace ns = (CodeNamespace)elm;
       ns.AddClass( HelloWord ,null,null,null,EnvDTE.vsCMAccess.vsCMAccessPublic);
      }
     }
    }
  }
 }
}