请问Session如何判断为空，又如何清空?

[denoxo]

是用Session["abc"]=null;
Session.Remove("aa");
谢谢！

[amendajing]

if(Session["abc"]!=null)
{
Session["abc"]=null;
}

[cocoguo]

Session.Remove("abc");//删除一个
Session.RemoveAll();//删除全部

[rickjelly2004]

if session("") is nothing then

[rickjelly2004]

session.Abandon

session.remove()

[yichuan1982]

if(Session[""]==null)

Session.Clear()
Session.remove()

[zcrong]

up

[denoxo]

Session["abc"]=null;
与
Session.Remove("aa");
有什么样区别

[mouse159]

hehe

[joinus97]

If you are using ASP 3.0 (the version of ASP that comes with Windows 2000 / IIS 5) then you can use the following syntax:

Session.Contents.Remove "name"

where Name is the name of the Session variable you wish to remove. Removing Session variables in this way has its advantages over using the following method:

Session("Name") = Null

Namely, the above method (setting a Session variable to Null) only removes the memory associated with the Session variable itself... the Session object still maintains a reference to it, though. Each Session variables is stored in the Session object with a key/item pair, similar to the Scripting.Dictionary object. Therefore, using the Null method above, you are not removing the key from the Session Contents collection that contains the reference to the variable...

With the Remove method that we looked at first, you are removing both the key and item associated with a Session variable. There is also a RemoveAll method that can be used to scrap all of the Session variables completely:

Session.Contents.RemoveAll

Again, the Remove and RemoveAll methods are new to ASP 3.0. If you have ASP 2.0, you will need to use the Null method