Q: global variable

[Guest]

Hello,
What is the life span of public variable defined in the class.
Is there any way to define a global variable in aps.net, and use it in all
the following pages.
Thanks,
Jim.

 

[Eliyahu Goldin]

What is the life span of public variable defined in the class.
One page building one response, unless it is static.

Is there any way to define a global variable in aps.net, and use it in all
the following pages.

There is a number of ways. Session variables for the scope of a session.
Application cache, static variables for the scope of application. There are
also some other ways.

Eliyahu

 

[Scott Allen]

The life span of a variable is as long as the class instance it is
associated with, and the object will live for as long as you hold a
reference to the object. We typically don't hold a reference to a Page
object since they are only used to process a single request. You could
put an object reference inside the Session, Cache, or Application
objects to keep the object around a bit longer.

You can also mark a field as static (shared in VB.NET) and the field
will be around for the duration of the application. A static field
also means there is only one instance of the field in the entire
application - no matter how many objects get created - so you have to
be sure this is what your design really calls for. Globals like this
are a double edged sword.

 

[Kevin Spencer]

The life span of any variable is the life span of the object in which it is
declared. A public variable defined in a class is part of the class, and
lives for the life of the class.

However, don't make any assumptions yet. A Page class lives from the time
the Page is requested until the time the Response is sent. Not long at all.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.

 

[IPGrunt]

Subject: Re: global variable
From: "Kevin Spencer" <[email protected]>
Newsgroups: microsoft.public.dotnet.framework.aspnet

The life span of any variable is the life span of the object in which it is
declared. A public variable defined in a class is part of the class, and
lives for the life of the class.

However, don't make any assumptions yet. A Page class lives from the time
the Page is requested until the time the Response is sent. Not long at all.

--
HTH,

Kevin Spencer
Microsoft MVP
.Net Developer
Neither a follower nor a lender be.

Jim,

In an OOP language like C#, you have many options as to variable
category and the scoping. Note the URLs below wrap.

See

http://msdn.microsoft.com/library/default.asp?url=/library/en-
us/csspec/html/vclrfcsharpspec_5_1.asp

and

http://msdn.microsoft.com/library/default.asp?url=/library/en-
us/csspec/html/vclrfcsharpspec_3_7.asp


The best way to implement a "global" variable is through the use of a
static class.

-- ipgrunt

 

[Ranv]

Hello,
What is the life span of public variable defined in the class.
Is there any way to define a global variable in aps.net, and use it in all
the following pages.
Thanks,
Jim.

Trying using the Session object. For instance, lets say you want to
store a user name that you need for all your pages, the code would
look like this: (I'm using C#)

Session.Contents["username"] = "jim";

and then in another page, to retrieve this information, you would:

string user;
user = Session["username"].ToString();

That's pretty much it, the name of the array index "username" is also
up to you, you can call it whatever you want. Check out MSDN for a
further explanation of the session object. Hope that helps.