关于Cookies的问题？？？

Question

请问下面的代码的含义，用.net写怎么写？？（C＃）
If isnull(usercookies) or usercookies="" Then usercookies="0"
select case usercookies
case "0"
Response.Cookies(Dvbbs.Forum_sn)("usercookies") = usercookies
case 1
    Response.Cookies(Dvbbs.Forum_sn).Expires=Date+1
Response.Cookies(Dvbbs.Forum_sn)("usercookies") = usercookies
case 2
Response.Cookies(Dvbbs.Forum_sn).Expires=Date+31
Response.Cookies(Dvbbs.Forum_sn)("usercookies") = usercookies
case 3
Response.Cookies(Dvbbs.Forum_sn).Expires=Date+365
Response.Cookies(Dvbbs.Forum_sn)("usercookies") = usercookies
end select
Response.Cookies(Dvbbs.Forum_sn).path = Dvbbs.cookiepath
Response.Cookies(Dvbbs.Forum_sn)("username") = regname
Response.Cookies(Dvbbs.Forum_sn)("userid") = Dvbbs.UserID
Response.Cookies(Dvbbs.Forum_sn)("password") = TruePassWord
Response.Cookies(Dvbbs.Forum_sn)("userclass") = userclass
Response.Cookies(Dvbbs.Forum_sn)("userhidden") = userhidden
rem 清除图片上传数的限制
Response.Cookies("upNum")=0
Dim iUserInfo
iUserInfo = Session(Dvbbs.CacheName & "UserID")
iUserInfo(35) = TruePassWord
Session(Dvbbs.CacheName & "UserID") = iUserInfo
End If

Answer 1

if(usercookies == null  )
{
switch(usercookies)
{
case "0":
{
//
break;
}
case "1":
{
//
break;
}
}
}