C#创建文件夹

      string month = DateTime.Now.ToString("yyyyMM");//月份
      string date = DateTime.Now.ToString("dd");//天数
      string jobNumber = "123456";
      
      StringBuilder imgPath = new StringBuilder();
      imgPath.Append(SystemIni.PhotoPath);
      imgPath.Append(month).Append("\\");
      imgPath.Append(date).Append("\\");
      imgPath.Append("证件正反面文件").Append("\\");
      if (System.IO.Directory.Exists(imgPath.ToString())==false)
      {       
         System.IO.Directory.CreateDirectory(imgPath.ToString());
      }