Problem: Value of a variable is lost on second postback

[summer00]

Hi everyone,

I found that the value of a variable(string type for example) is lost
after the aspx page postback.

E.G:


private void Page_Load(object sender, System.EventArgs e)
{
if(!IsPostBack)
abc = "xyz";
}
private void Command1_Click(object sender,System.EventArgs e)
{
Response.Write(abc);
}



I have assigned the abc value to "xyz" , but after i click the command
button, i found that the value of abc is lost. The code "
Response.Write(abc)" shows nothing .May i know what's wrong with it ?
Thx a lot

*-----------------------*
Posted at:
www.GroupSrv.com
*-----------------------*

 

[Eliyahu Goldin]

Web pages don't live between postbacks. They are built as needed when
requests arrive. There is a number of ways of making information persistent.
Session, viewstate, application cache.

Eliyahu

 

[Juan T. Llibre]

Nothing's wrong with it.

You are specifying that, upon first access (!IsPostBack)
the value of "abc" should be "xyz" and that when the page
*is* a postback ( i.e., when you post the page back by
clicking the command button ) the value of "abc" should
remain as "abc".

When the page is posted back, the condition (!IsPostBack)
is false, and the "abc" variable value will still be "abc".

If you want "abc" to always have the value "xyz",
you shouldn't specify

if(!IsPostBack)
abc = "xyz";

in the Page_Load event.



Juan T. Llibre
ASP.NET MVP
===========