Why can't I get the value when I disable a control?

[Mike Hnatt]

I have code that will set a drop-down list value to "xyz" and the .Enabled
property to False. However, when I do that I can no longer retrieve the
value "xyz" upon postback. It is as if I set the .Visible property to False
as well and the control wasn't rendered, but I did not. If you View Source
of the rendered HTML, you can see that the control is indeed still intact
(everything is the same except the disabled argument is set to "disabled").

Why can't I get the value when I disable a control?

Thanks,
Mike

 

[Wim Hollebrandse]

That is by design.

What you can do however is to set a hidden form field to the value of the selectbox just before you disable it, and retrieve that instead.

Hope that helps,
Wim Hollebrandse
http://www.wimdows.net
http://www.wimdows.com

 

[L. L.]

Hi Wim,

Is it by design for version 1.1? I am using 1.0 and this is not happening.


Thanks,

Lenny

That is by design.

What you can do however is to set a hidden form field to the value of the

selectbox just before you disable it, and retrieve that instead.

 

[Mike Hnatt]

Thanks Wim,
Good idea,
Mike

That is by design.

What you can do however is to set a hidden form field to the value of the

selectbox just before you disable it, and retrieve that instead.

 

[David]

Is it by design for version 1.1? I am using 1.0 and this is not happening.

It's by design in the HTML spec. ASP.NET versions have nothing to do
with it. Browsers aren't supposed to submit the values of disabled
controls.

 

[Wim Hollebrandse]

It's as per the W3C HTML standards.

http://www.w3.org/TR/REC-html40/interact/forms.html#successful-controls

I am pretty sure it is the same for version 1.0 as its a browser/HTML issue and does not really have any bearing on the serverside controls (as long as they render the disabled attribute).

Cheers,
Wim
http://www.wimdows.net
http://www.wimdows.com

 

[L. L.]

Mike,

For a dropdown, you don't set the value like
DropDownList1.SelectedItem.Value = "xyz". Instead, you do this
DropDownList1.SelecteIndex = i; //i is the index of value "xyz" in the
dropdown, starting from 0.

Make sure only set it once in the Page_Load event like,

if(!Page.IsPostBack)

{

DropDownList1.SelectedIndex = 1;

DropDownList1.Enabled = false;//you can still get the value on postaback

DropDownList1.Visible = false;//you can still get the value on postaback

}

In the postback, I am sure you can get the value through code like,

string ddlvalue = DropDownList1.SelectedItem.Value;

It doesn't matter the ddl is enabled or not. The ddl can even be invisible.

L.L.