Page.IsPostBack Property

[nly]

Page.IsPostBack Property

"The Page_Load subroutine runs EVERY time the page is loaded. If you want to
execute the code in the Page_Load subroutine only the FIRST time the page is
loaded, you can use the Page.IsPostBack property. If the Page.IsPostBack
property is false, the page is loaded for the first time, if it is true, the
page is posted back to the server (i.e. from a button click on a form)..."

Let's say we have this in a "body" of an aspx page:

<form runat="server">
<h3><asp:label id="lbl1" runat="server" /></h3>
<asp:button text="Submit" onclick="submit" runat="server" />
</form>

What does it mean by "the page is posted back to the server"? What's exactly
posted back here in the above example?

Thanks in advance!

 

[Tasos Vogiatzoglou]

First of all the onclick attribute in an asp:button components must a
method in your code-behind.

Postback is generated every time you raise an event from a server-side
control. Thus when you click the "asp:button" text the page will be
posted-back.


Hope this helped ...

 

[nly]

First of all the onclick attribute in an asp:button components must a
method in your code-behind.

Postback is generated every time you raise an event from a server-side
control. Thus when you click the "asp:button" text the page will be
posted-back.

What does it mean by "the page ...(is)...posted-back"?

 

[clintonG]

It means the page posts back to itself. By default all web forms use
method="post" in the form of the page.

<%= Clinton Gallagher
METROmilwaukee (sm) "A Regional Information Service"
NET csgallagher AT metromilwaukee.com
URL http://metromilwaukee.com/
URL http://clintongallagher.metromilwaukee.com/

 

[Cor Ligthert [MVP]]

nly,

Have a look at your HTML forms part of your page.

That information is posted back if you click on a control that has
autosentback set to true. Autosentback is default by some controls as the
button, however default false by some as by instance the listbox.

If it is "sentback", than everytime the data can be processed. The
IsPostBack is most often placed in the load event of the page in the code
behind.

By instance

if (IsPostBack) {
//Get Information From Database
}
else{
//Get information from Session item
}

I hope this helps,

Cor

 

[Cor Ligthert [MVP]]

Oeps,

Typed it here in the message

if (IsPostBack) {
//Get Information From Session
}
else{
//Get information from DataBase
}

I use mostly the ! situation.



Cor