Calling Javascript on page load

mellomel70 · Aug 2, 2011

Hi - I have an ASP.Net 2.5 application and I need to call a javascript function when one of the pages loads initially. I've tried:

Code:

string ScriptToCall = @"EnableCheckboxes(" + cblDetails.ClientID + ", false);";
ClientScript.RegisterStartupScript(this.GetType(), "addScript", ScriptToCall, true);

where EnableCheckboxes is a javascript function on the page. This doesn't work (doesn't disable the CheckBoxList), although the EnableCheckboxes function DOES work when I call it in other ways, so I'm sure that the problem is that I'm not calling it properly on page load.

I've tried:

Code:

ClientScript.RegisterStartupScript(this.GetType(), "addScript", "alert('Hello');", true);

which DOES work, so I know I'm on the right track, but how do I do this?

Thanks!

BillyRayPreachersSon · Aug 2, 2011

If you want to know how to do this using .Net syntax, then you're probably better off asking in a .Net forum rather than here.

That aside, a cast-iron way of detecting page load is simply to hook into the window's 'onload' event. Here's how I would do it in Firefox / Chrome / Safari:

Code:

function pageLoad() {
   // do something
}

window.addEventListener('load', pageLoad, false);

You'll need to add code for IE compatibility, depending on your needs (investigate 'attachEvent').

Dan

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vacunita · Aug 2, 2011

An easier way is to simply add the function call to the body's onload event directly.

Code:

<body onload="myfuinction();">

----------------------------------
Phil AKA Vacunita
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mellomel70 · Aug 2, 2011

Alas, I think I need to do this via .Net because I only want to call this when the page first loads, not on every page load. I'll post on a .Net or C# forum, thanks!

mellomel70 · Aug 3, 2011

A co-worker helped me out. Here's how you do it: Put the following code under the CheckBoxList definition on the aspx page:

Code:

<script type="text/javascript" language="javascript">
                                var controlID = '<%= cblDetails.ClientID %>';
var chk = document.getElementById(controlID);
chk.disabled = true;
</script>

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Calling Javascript on page load

mellomel70

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BillyRayPreachersSon

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vacunita

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mellomel70

Programmer

mellomel70

Programmer

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