通过C#代码压缩后路径过长问题。。。

String the_rar;
RegistryKey the_Reg;
Object the_Obj;
String the_Info;
ProcessStartInfo the_StartInfo;
Process the_Process;
try
{
the_Reg = Registry.ClassesRoot.OpenSubKey(@"Applications\WinRAR.exe\Shell\Open\Command");
the_Obj = the_Reg.GetValue("");
the_rar = the_Obj.ToString();
the_Reg.Close();
the_rar = the_rar.Substring(1,the_rar.Length - 7);
the_Info = "a " + "1.rar " + " " + Server.MapPath("~/upload/1.txt") + " " + Server.MapPath("~/upload/2.txt");
the_StartInfo = new ProcessStartInfo();
the_StartInfo.FileName = the_rar;
the_StartInfo.Arguments = the_Info;
the_StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
the_StartInfo.WorkingDirectory = Server.MapPath("~/upload");//获取或设置要启动的进程的初始目录。
the_Process = new Process();
the_Process.StartInfo = the_StartInfo;
the_Process.Start();
Response.Write("压缩成功");
}
catch (Exception ex)
{
Response.Write(ex.ToString());
}压缩时保留了文件原来的绝对路径，解压出来的路径相当多    怎么修改啊啊啊啊？？？？？