string path = @"E:\33\2323\test\Demo\";
                path = Regex.Match(path,@".*?(?=[^\\]+?\\$)").Value;
                //E:\\33\\2323\\test\\

------解决方案--------------------
C# code

var dir = new System.IO.DirectotyInfo(@"E:\33\2323\test\Demo\");
var dirp = dir.ToString();