This is driving me nuts! I get this error:

"Error 2 'EnableLoad' is not a member of 'ASP.frmquestionselection_aspx'. D:\Projects\2008\Interview Questionnaire\frmQuestionSelection.aspx 28":

From this HTML line:

<asp:DropDownListID="ddIQList"runat="server"OnSelectedIndexChanged="EnableLoad()">

Yet this works:

<asp:DropDownListID="ddIQList"runat="server"onclick="EnableLoad()">

Here's the script in BOTH instances:

<scriptlanguage='VBScript'type='text/vbscript'>
<!--
EnableLoad()


sub EnableLoad()
if frmQuestionSelection.ddIQList.SelectedIndex > -1 then
frmQuestionSelection.btnLoad.disabled=false
else
frmQuestionSelection.btnLoad.disabled=true
endif
endsub

Intelisense says onselectedindexchanged is a valid event for a select. So, why is the EnableLoad() script found by the onclick event but NOT by the onselectedindexchanged event?

OnClick is not a server side event of the DDL, and thus the *client side VB script* method EnableLoad can be used *at the client* when the control is clicked. The compiler does not try to look for a server method.

OnSelectedIndexChanged on the other hand is a server side event. As such, the compiler looks for a server side method implemented in C# or VB in the page that contains the controls declaration.

Does this help?

Imar
---------------------------------------------------------------------------------------------------------------------
Imar Spaanjaars
http://Imar.Spaanjaars.Com
Follow me on Twitter.

Everyone is unique, except for me.
Author of Beginning ASP.NET 4 : in C# and VB, Beginning ASP.NET 3.5 : in C# and VB, and ASP.NET 2.0 Instant Results.
While typing this post, I was listening to: What Your Soul Sings by Massive Attack (Track 2 from the album: 100th Window) What's This?

Absolutely OK. But that doesn't mean it's OK to start using VB Script for server side event handlers. There are limits, you know.... ;-)

Cheers,

Imar
---------------------------------------------------------------------------------------------------------------------
Imar Spaanjaars
http://Imar.Spaanjaars.Com
Follow me on Twitter.

Everyone is unique, except for me.
Author of Beginning ASP.NET 4 : in C# and VB, Beginning ASP.NET 3.5 : in C# and VB, and ASP.NET 2.0 Instant Results.
While typing this post, I was listening to: Pray for Rain by Massive Attack (From the album: Heligoland) What's This?

After wrestling with it for a couple of hours I decided to go with server side code (and not vbSCRIPT, of course!) I think the VS 2008 ought not list OnSelectedIndexChanged as a valid HTML attribute on the asp:button in intellisense if it won't compile with that event selected.


As to the sig, I only wanted a vbscript solution IF the intended solution was to be implemented client side, of course. I was hoping to avoid the round trip to the server with AJAX, but in retrospect, it doesn't really matter if a callback occurs in this instance. Ubiquitous support for JS leads some to supply a JS solution even though VS was specifically requested, and still others feel the strange need to lecture me about using it. The sig was intended to prevent responses that would not prove helpful and not as an insult to those who prefer JS.

Quote:

I think the VS 2008 ought not list OnSelectedIndexChanged as a valid HTML attribute on the asp:button in intellisense if it won't compile with that event selected.

Either you didn't show the complete code, or it's not doing this. It shows OnSelectedIndexChanged for the DropDownList, which is a valid event for this control at the server.

From what I can see, both event handlers are valid, be it both in a different context.

If you wanted to, you could use simple <select /> items instead and use the client side onchange, optionally with a runat="server" attribute so the lists can be reached from server side code.

Quote:

As to the sig, I only wanted a vbscript solution IF the intended solution was to be implemented client side, of course. I was hoping to avoid the round trip to the server with AJAX, but in retrospect, it doesn't really matter if a callback occurs in this instance. Ubiquitous support for JS leads some to supply a JS solution even though VS was specifically requested, and still others feel the strange need to lecture me about using it. The sig was intended to prevent responses that would not prove helpful and not as an insult to those who prefer JS.

I know, and completely understand; hence the smiley in my reply ;-)

Cheers.

Imar

__________________
Imar Spaanjaars
http://Imar.Spaanjaars.Com
Follow me on Twitter

Author of Beginning ASP.NET 4.5 : in C# and VB, Beginning ASP.NET Web Pages with WebMatrix
and Beginning ASP.NET 4 : in C# and VB.
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