1:      public class MyOpenFileDialog : CommonDialog

   2:      {

   3:        private string _filename;

   4:        private string _title;

   5:   

   6:        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]

   7:        internal class OpenFileName

   8:        {

   9:          internal int structSize;

  10:          internal IntPtr owner;

  11:          internal IntPtr instance;

  12:          internal string filter;

  13:          internal string customFilter;

  14:          internal int maxCustFilter;

  15:          internal int filterIndex;

  16:          internal string file;

  17:          internal int maxFile;

  18:          internal string fileTitle;

  19:          internal int maxFileTitle;

  20:          internal string initialDir;

  21:          internal string title;

  22:          internal Int16 flags;

  23:          internal Int16 fileOffset;

  24:          internal int fileExtension;

  25:          internal string defExt;

  26:          internal IntPtr custData;

  27:          internal IntPtr hook;

  28:          internal string templateName;

  29:        }

  30:   

  31:        [DllImport("comdlg32.dll", CharSet = CharSet.Auto, SetLastError = true)]

  32:        internal static extern bool GetOpenFileName ([In, Out] OpenFileName ofn);

  33:   

  34:        public override void Reset ()

  35:        {

  36:          this._filename = null;

  37:          this._title = null;

  38:          //Other reset code here...

  39:        }

  40:   

  41:        protected override bool RunDialog (IntPtr hwndOwner)

  42:        {

  43:          OpenFileName ofn = new OpenFileName();

  44:          ofn.file = new string(' ', 0x2000);

  45:          ofn.owner = hwndOwner;

  46:          ofn.instance = Marshal.GetHINSTANCE(typeof(MyOpenFileDialog).Module);

  47:          ofn.title=_title;

  48:          ofn.maxFile = 0x2000;

  49:          ofn.structSize = Marshal.SizeOf(ofn);

  50:          bool ret = GetOpenFileName(ofn);

  51:          if(ret)_filename = ofn.file.TrimEnd();  

  52:          return ret;      

  53:        }

  54:   

  55:        public string FileName

  56:        {

  57:          get { return _filename; }

  58:        }

  59:        public string Title

  60:        {

  61:          get { return _title; }

  62:          set { _title = value; }

  63:        }

  64:    

  65:      }