public string GetDirectoryName(string path)
{
if (string.IsNullOrEmpty(path))
return null;
char ending = path[path.Length - 1];
if (ending == Path.DirectorySeparatorChar || ending == Path.AltDirectorySeparatorChar)
path = path.Substring(0, path.Length - 1);
return Path.GetDirectoryName(path);
}