IsPostBack always returns false

Question

I've encountered a weird problem. Everytime I refresh the page, IsPostBack is false.
To make sure nothing in my contents or master pages is causing this, I have created an empty web form and fired it up in debug mode. still, on postbacks, I have IsPostBack set to false.

I have enableSessionState="true" and <sessionState timeout="30" /> in web.config.

It's driving me nuts!

Update: I refresh the page by hitting F5. Based on answers this should not cause a postback. I'd like to know when a use refreshes the page (even manually) and prevent some modifications to db).
Is there a solution for this?

When you say `refresh the page`, do you mean manually or actually by clicking on a server side control such as a button? — keyboardP, Jul 07 '11 at 16:47
@Kamyar - Pressing F5 does not cause a postback, so there's nothing wrong with your code. (Check answers) — keyboardP, Jul 07 '11 at 16:49
Sounds like you need some other mechanism to detect that the page was refreshed, like a counter. Viewstate, Session, hidden field - there are many options. — TheGeekYouNeed, Jul 07 '11 at 16:52
Anyone can guide me how to know when the user refreshes the page manually? should I go throught referrer to find out? — Kamyar, Jul 07 '11 at 16:52
@TheGeekYouNee: Thanks. Got it now. To whoever downvoted this... Care to share why?!!! — Kamyar, Jul 07 '11 at 16:54
@Kamyar see the edit to my answer for a way to achieve this. — Kyle Trauberman, Jul 07 '11 at 16:56

Kyle Trauberman · Accepted Answer · 2011-07-07T16:55:45.420

Refreshing the page (pressing F5 or the refresh button in your browser) is not a postback. A postback occurs when a button is clicked, a dropdown is changed, or some other event on the page that causes data to be sent to the server (via HTTP POST, hence the name 'postback')

~~Your question doesn't make it clear whether you are refreshing the page manually or posting back to the server via a button click or some other event.~~

Since you are manually refreshing the page, IsPostBack will always be false.

There are two types of requests (in a sense) in ASP.NET:

a regular request (e.g. the user is loading the page for the first time)
a postback (e.g. a button was clicked on the page, sending data to the server)

If you want to track if a user has been to a page before in either case, you'll need to track that your self. You can set a variable in the Session to do this:

Session["UserHasVisitedThisPageBefore"] = true;

Then you can check it in place of your current IsPostBack check:

if(Session["UserHasVisitedThisPageBefore"] != null && (bool)Session["UserHasVisitedThisPageBefore"])
{
    // stuff here
}

Thanks for the answer. But using session state variables is not a good choice, since I have to remove it whenever user navigates aways from the page otherwise, If user goes to some other pages and comes back, it's still false. I think using hidden fields in the best choice for handling this. — Kamyar, Jul 07 '11 at 17:04

keyboardP · Answer 2 · 2011-07-07T16:53:29.700

5

When you refresh the page, the IsPostBack should be false. It becomes true when a control has caused a postback, such as a server side button.

Edit - To answer your update: You can use IsPostBack to determine whether or not you want to update the database. If it's false, don't update the database otherwise update it.

 if(IsPostBack)
 {
   //Update DB
 }

edited Jul 07 '11 at 16:53

answered Jul 07 '11 at 16:47

keyboardP

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Thanks for the answer. But my problem was when the user refreshed the page, IsPostbBack was always false. Kyle's answer proposed I should use session variables. +1 though. – Kamyar Jul 07 '11 at 17:01

score 2 · Answer 3 · answered Jul 12 '13 at 20:51

2

I had this problem of IsPostBack always being false in a particular project that had XSL rendering the markup. So instead of relying on .NET's IsPostBack property, I simply checked Request.HttpMethod.

e.g. if I needed to check !IsPostBack, I instead checked if Request.HttpMethod == "GET"

e.g. if I needed to check IsPostBack, I instead checked if Request.HttpMethod == "POST"

answered Jul 12 '13 at 20:51

CaptainJanuary

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Nice idea ... except my controls came back empty! – Gary Huckabone Jan 27 '23 at 22:15

score 2 · Answer 4 · answered Jul 07 '11 at 16:56

2

Sounds like you need some other mechanism to detect that the page was refreshed, like a counter. Viewstate, Session, hidden field - there are many options.

answered Jul 07 '11 at 16:56

TheGeekYouNeed

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score 1 · Answer 5 · answered Jul 07 '11 at 16:50

Every time you refresh page you basically perform GET request to you page. GET means, load the page without any change of state server. IsPostBack = false is absolutely right behaviour!

The postback would occur on page, if you do POST to it. Then the server side form is being submitted or web control with autoPostBack is triggered - it would cause a postback. IsPostBack will be true.

IsPostBack always returns false

5 Answers5