Events for Controls added in code

[Dominique Vandensteen]

I have a Table to which I add a LinkButton in the PreRender event
The LinkButton is visible on the webpage but when I click it,
the LinkButton_Click method is not called and the page just "reloads"

anybody an idea what I'm missing here?



Private Sub Page_PreRender(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MyBase.PreRender
Dim addRootLink As New LinkButton
AddHandler addRootLink.Click, AddressOf LinkButton_Click

... add linkbutton to table
End Sub

 

[Yunus Emre ALPÖZEN [MCAD.NET]]

you should manually set its event handler something like this;

LinkButton lb = new LinkButton();
lb.Click+=new EventHandler(lb_click)

 

[Brock Allen]

PreRender is too late in the page lifecycle to add events such as click and
change event handlers, as that stage has already passed. You should add these
events sometime in or prior to Page_Load.

-Brock
DevelopMentor
http://staff.develop.com/ballen

 

[Dominique Vandensteen]

thx
with some gymnastics I can make this work...

is there a place where I can find the order of the events?

 

[Brock Allen]

is there a place where I can find the order of the events?

The MSDN docs of course have it buired in there somewhere. I've recently
seen a blog post with a graphic of the order. In general they are:

Page and Controls Created
Page_Init
ViewState Loaded
Post data Loaded
Page_Load
Server Side Validation
Any Change Events
Any Click Event
Page_PreRender
Render
Page_Unload
Page is discarded

-Brock
DevelopMentor
http://staff.develop.com/ballen

 

[Dominique Vandensteen]

Thanks for the info

but now, if I need to create events depending on a clicked button...
what is the right way to do it then?

this is in fact my case, but for now I worked around it by disable-ing my
buttons

 

[Brock Allen]

but now, if I need to create events depending on a clicked button...

what is the right way to do it then?

You dynamically add the control in the button click event, then upon every
postback you need to recreate the controls that were previousally dynamically
created. The trick is how to "remember" on the next postback what you had
previously created. I'd suggest using ViewState. Here's a sample I posted
a while back:

http://groups-beta.google.com/group...ic+controls+viewstate&rnum=1#a5717a97bd32c450

-Brock
DevelopMentor
http://staff.develop.com/ballen

 

[Scott Mitchell [MVP]]

is there a place where I can find the order of the events?

Dominique, check out these two articles:

Understanding ASP.NET ViewState
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/viewstate.asp
(see the "The ASP.NET Page Lifecycle" section in particular)

-and-

The ASP.NET Page Object Model
http://msdn.microsoft.com/asp.net/c.../en-us/dnaspp/html/aspnet-pageobjectmodel.asp

hth