Use javascript to determine if an ASP.NET page is a postback

Question

Is it possible to determine if an ASP.NET page is a postback from javascript? So basically a javascript equivalent of C# Page.IsPostBack.

Thanks.

score 14 · Accepted Answer · edited Mar 10 '11 at 08:12

14

I would just put a render tag in the javascript

var isPostBack = <%= Page.IsPostBack ? "true" : "false" %>;

Putting the "true" and "false" as strings should be done to eliminate any possible issues converting the type to a string as in C# true.ToString() is usually "True" which is an error in javascript.

edited Mar 10 '11 at 08:12

moinudin

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answered Jan 02 '09 at 16:05

Bob

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This is something we do as well, very handy +1 – Kieran Senior Jan 02 '09 at 16:06
2

Of course, at this point, it is technically "wasPostBack". :P – patridge Jan 02 '09 at 17:16

score 2 · Answer 2 · answered Jan 02 '09 at 16:05

2

Sure. Just use your server code to write out a javascript flag, if you really need this.

But I suspect you're barking up the wrong tree here.

answered Jan 02 '09 at 16:05

Joel Coehoorn

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score 0 · Answer 3 · answered Jan 06 '09 at 17:02

I'm not exactly sure of what you are trying to do but you might want to look into the PageRequestManagerClass:

http://www.asp.net/AJAX/Documentation/Live/ClientReference/Sys.WebForms/PageRequestManagerClass/default.aspx

It exposes events for all different parts of the request.

Use javascript to determine if an ASP.NET page is a postback

3 Answers3

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