disable scroll

[Guest]

hey all,

can someone please tell me if you can disable the scroll button for a
dropdownlist. For example, when you select an item in a dropdownlist and it
still has focus and you accidently hit scroll wheel on your mouse the
selected item changes.

can this be disabled?

thanks,
rodchar

 

[Kevin Spencer]

No.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Ambiguity has a certain quality to it.

 

[S. Justin Gengo]

Rodchar,

Depending on how your site is set up you may be able to take care of this. I
find the list still being selected to be a problem after a page is posted
back (say when filtering a datagrid) and then, when the filtered results are
returned the scroll wheel is accidentally clicked starting the process over
again.

I use a javascript on post back to place the focus onto something else on
the page.

So, for example, in the post back event handler of the submit button (or the
drop down list itself if it's set to autopostback) I use a startup script
like:

Page.RegisterStartupScript("MyFocusScript", "<script
language=""javascript"">document.getElementById('MyDataGridClientIdHere');</script>")

--
Sincerely,

S. Justin Gengo, MCP
Web Developer / Programmer

www.aboutfortunate.com

"Out of chaos comes order."
Nietzsche

 

[Damien]

No.

--
HTH,

Kevin Spencer
Microsoft MVP
.Net Developer
Ambiguity has a certain quality to it.

Sorry, cant see original message, but I'd say try something like the
following:

<aspropDownList id="blah" runat="server" onmousewheel="return
false;"></aspropDownList>

The onmousewheel will probably get a syntax wobbly line, but I think
that should work (or you can add it via code if you want/if it doesn't
work)

Damien

 

[Guest]

that worked great, thanks. thanks everyone for the great feedback.

 

[Kevin Spencer]

<aspropDownList id="blah" runat="server" onmousewheel="return

false;"></aspropDownList>

The onmousewheel will probably get a syntax wobbly line, but I think
that should work (or you can add it via code if you want/if it doesn't
work)

This will not prevent the select object from scrolling. I tested it with a
pure HTML form. In addition, the "onmousewheel" event is proprietary to
Microsoft IE.

Justin did have an idea I hadn't thought of. However, he didn't post the
JavaScript correctly (it referenced the element, but didn't write what it
should do):

Page.RegisterStartupScript("MyFocusScript", "<script
language=""javascript"">document.getElementById('MyDataGridClientIdHere');</script>")

I believe he meant:

Page.RegisterStartupScript("MyFocusScript", "<script
language=""javascript"">document.getElementById('MyDataGridClientIdHere').focus();</script>")

This does not prevent the user from putting the focus on the select object
and scrolling the mouse wheel, however. It does set the focus elsewhere when
the page loads.

On the other hand, it did make me think. Assuming again that *all of your
users are using IE*, you COULD keep the "onmousewheel" event from changing
the SelectedIndex of the select object. This would require a global
JavaScript variable to store the current SelectedIndex of the select object
in, and another to prevent the select object's "onchange" event from doing
anything. You could define a JavaScript function that handles the
"onmousewheel" event. It would check the global Selectedindex variable, set
the global "prevent" variable to true, set the select object's SelectedIndex
to the value of the variable, set the window.event.cancelBubble property to
true, which cancels the event from bubbling up, and reset the global
"prevent" variable to false. In addition, you would need an "onchange" event
for the select object itself, which first checks the prevent variable, and
if false, sets the global SelectedIndex variable to the new select object's
SelectedIndex.

Now, if anyone is NOT using IE, this should not prevent anything from
happening normally, but will prevent the "onmousewheel" event from changing
the SelectedIndex property of the select object on IE.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Ambiguity has a certain quality to it.

 

[S. Justin Gengo]

Kevin,

Thanks for noticing that I forgot .focus() in that script!

--
Sincerely,

S. Justin Gengo, MCP
Web Developer / Programmer

www.aboutfortunate.com

"Out of chaos comes order."
Nietzsche

 

[Damien]

This will not prevent the select object from scrolling. I tested it with a
pure HTML form. In addition, the "onmousewheel" event is proprietary to
Microsoft IE.

Well, it seems to work here. Admittedly, yes, only for IE. But shooting
for the LCD (IE user insult coming up here), it's those users who are
least likely to spot what is happening with the mousewheel.

I'm using IE 6, and the following markup works:

<html>
<head>
<title>Must have a Title</title>
</head>
<body>
<select onmousewheel="return false;"><option
value="1">1</option><option value="2">2</option><option value="square
root of 2">3</option></select>
</body>
</html>

(Incidentally, it also appears to work in Opera?)

Damien

 

[Kevin Spencer]

Well, I'll be darned, Damien. I tested your code, and it did indeed work! I
wish I had posted my own experiment so that I could see what the difference
was, but it is lost to me forever. Perhaps it was just too early in the
morning for me, I just don't know.

In any case, I stand corrected. My apologies.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Ambiguity has a certain quality to it.