C#

class MyFile : FileSystemInfo
 {
     private FileInfo _strFile;
     public MyFile(FileInfo strFile)
     {
         _strFile = strFile;
     }

     public override void Delete()
     {
         _strFile.Delete();
     }

     public override bool Exists
     {
         get
         {
             if (_strFile.Exists)
             {
                 return true;
             }
             else
             {
                 return false;
             }

         }
     }

     public override string Name
     {
         get { return _strFile.Name;}
     }
 }

class MyFiles : IEnumerable<MyFile>
 {
     private string _directoryPath;
     private string _fileExtension = "xml";

     public MyFiles(string directoryPath)
     {
         _directoryPath = directoryPath;
     }

     public string FileExtension
     {
         get { return _fileExtension; }
         set { _fileExtension = value; }
     }

     #region IEnumerable<MyFile> Members

     public IEnumerator<MyFile> GetEnumerator()
     {
         DirectoryInfo di = new DirectoryInfo(_directoryPath);
         FileInfo[] rgFiles = di.GetFiles("*." + _fileExtension);
         foreach (FileInfo fi in rgFiles)
         {
             MyFile ss = new MyFile(fi);
             yield return ss;
         }
     }

     #endregion

     #region IEnumerable Members

     IEnumerator IEnumerable.GetEnumerator()
     {
         DirectoryInfo di = new DirectoryInfo(_directoryPath);
         FileInfo[] rgFiles = di.GetFiles("*." + _fileExtension);
         foreach (FileInfo fi in rgFiles)
         {
             MyFile ss = new MyFile(fi);
             yield return ss;
         }
     }

     #endregion

 }

static void Main()
   {
       MyFiles myFS = new MyFiles(@"D:\TestInterface");
       foreach(MyFile FS in MyFiles)
       {
           Console.WriteLine(FS.Name);
           Console.ReadLine();
       }

   }

0:004> ~0e!clrstack -a
OS Thread Id: 0x1194 (0)
Child-SP         RetAddr          Call Site
RSP/REG          Object           Name
RSP/REG          Object           Name
RSP/REG          Object           Name
RSP/REG          Object           Name
RSP/REG          Object           Name
000000000012efe0 0000064280150182 TestDebugManaged1.Program.foo()
    PARAMETERS:
        this = 0x0000000002651ac8
    LOCALS:
        0x000000000012f000 = 0x0000000000000064
        0x000000000012f004 = 0x0000000000000001

RSP/REG          Object           Name
000000000012f020 000006427f67d4a2 TestDebugManaged1.Program.Main(System.String[])
    PARAMETERS:
        args = 0x0000000002651aa8
    LOCALS:
        0x000000000012f040 = 0x0000000002651ac8

0:004> !do 0x000000000012f000
<Note: this object has an invalid CLASS field>
Invalid object

0:004> !do 0x000000000012f004
<Note: this object has an invalid CLASS field>
Invalid object

namespace TestDebugManaged1
{
    class Program
    {
        void foo()
        {
            int a = 100;
            while (true)
            {
                Thread.Sleep(10000);
                a++;
            }
        }
        
        static void Main(string[] args)
        {
            Program instance = new Program();
            instance.foo();
            return;
        }
    }
}

namespace TestDebugManaged1
{
    class Program
    {
        void foo()
        {
            int a = 100;
            while (true)
            {
                Thread.Sleep(10000);
                a++;
            }
        }
        
        static void Main(string[] args)
        {
            Program instance = new Program();
            instance.foo();
            return;
        }
    }
}