Question

i have a small class with just a couple properties in it.

here is an example:

public class clsRepLogs

public string those;
public string these;

    public void setThoseandThese
    {
    //call a stored procedure
    //get results

    this.those = something;
    this.these   = somethingElse;
    }}

from my first.aspx.cs

i call the set function:

clsRepLogs cLog - new clsRepLogs()
cLog.setThoseandThese()

so now the properties have been assigned values.

i now want to use them in another aspx.cs file to populate a form… but can’t figure out how to get to them…

i tried

clsRepLogs cLog;

lblThese.text = cLog.these;

but it’s giving me an error: “Use of unassigned local variable ‘cLog’

basically, how do i tell it to use the values i’ve already assigned to that class instance from before?

i hope i’m explaining this right, but i might be way of on what i’m doing. any help appreciated.

Answer 1

It sounds like you want to access the same instance of the class from multiple ASPX pages. There are multiple ways to do this; a per-user solution is to use session state.

// page 1
var c = new clsRepLogs();
c.setThoseAndThese();
Session["mykey"] = c;

// page 2
var c = (clsRepLogs)Session["mykey"];

“mykey” can be any string. You may also want to check if Session contains the value before accessing it, e.g. if( Session["mykey"] != null ){ ... }

Keep in mind:

• Session isn’t durable; restarting the web worker process will reset all in-process sessions.
• It’s usually not a good idea to store many large objects in Session.
• If the data is confidential, be aware of Session fixation attacks.
• Session can be load balanced across servers, so this solution will scale.

For reference (alternative approaches):

• You could use the Cache object when you don’t care about per-user isolation and want control over data expiration.
• You could use the Application object; similar to Cache but no control over expiration.
• You could store the object in the database and load it on each page. This is useful when you to don’t want a heavy session, and/or wish to save the data more permanently (such as a shopping cart which persists across multiple sessions).