字符串编码转换Unicode>GB2312

        string uni = "\u7535\u4fe1";        Console.Write(GetString(Encoding.Unicode, Encoding.GetEncoding("GB2312"), uni));

    public static String GetString(Encoding source,Encoding dest,String soureStr)
    {
        return dest.GetString(Encoding.Convert(source, dest,source.GetBytes(soureStr)));                           
    }