问如何在C#中获得与文件扩展名相关的推荐程序

EN

public IEnumerable<string> RecommendedPrograms(string ext)
{
  List<string> progs = new List<string>();

  string baseKey = @"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\." + ext;

  using (RegistryKey rk = Registry.CurrentUser.OpenSubKey(baseKey + @"\OpenWithList"))
  {
    if (rk != null)
    {
      string mruList = (string)rk.GetValue("MRUList");
      if (mruList != null)
      {
        foreach (char c in mruList.ToString())
          progs.Add(rk.GetValue(c.ToString()).ToString());
      }
    }
  }

  using (RegistryKey rk = Registry.CurrentUser.OpenSubKey(baseKey + @"\OpenWithProgids"))
  {
    if (rk != null)
    {
      foreach (string item in rk.GetValueNames())
        progs.Add(item);
    }
    //TO DO: Convert ProgID to ProgramName, etc.
  }

  return progs;
  }

foreach (string prog in RecommendedPrograms("vb"))
{
  MessageBox.Show(prog);
}

public List<string> RecommendedPrograms(string ext)
{
  //Search programs names:
  List<string> names = new List<string>();
  string baseKey = @"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\." + ext;
  string s;

  using (RegistryKey rk = Registry.CurrentUser.OpenSubKey(baseKey + @"\OpenWithList"))
  {
    if (rk != null)
    {
      string mruList = (string)rk.GetValue("MRUList");
      if (mruList != null)
      {
        foreach (char c in mruList)
        {
          s = rk.GetValue(c.ToString()).ToString();
          if (s.ToLower().Contains(".exe"))
            names.Add(s);
        }
      }
    }
  }

  if (names.Count == 0)
    return names;

  //Search paths:
  List<string> paths = new List<string>();
  baseKey = @"Software\Classes\Applications\{0}\shell\open\command";

  foreach (string name in names)
    using (RegistryKey rk = Registry.CurrentUser.OpenSubKey(String.Format(baseKey, name)))
    {
      if (rk != null)
      {
        s = rk.GetValue("").ToString();
        s = s.Substring(1, s.IndexOf("\"", 2) - 1); //remove quotes
        paths.Add(s);
      }
    }

  if (paths.Count > 0)
    return paths;

  //Search pathes for Windows XP:
  foreach (string name in names)
    using (RegistryKey rk = Registry.LocalMachine.OpenSubKey(String.Format(baseKey, name)))
    {
      if (rk != null)
      {
        s = rk.GetValue("").ToString();
        s = s.Substring(1, s.IndexOf("\"", 2) - 1); //remove quotes
        paths.Add(s);
      }
    }

  return paths;
}