'$（<％= DDL.ID％>'）和$（'<％= DDL.ID％>'）之间的差异

Question

I was trying to bind an event to drop down list since yesterday nothing helped went to JavaScript chat room no one was able to find a fix to my problem, but then I somehow tried to bind my drop down list as following

$('<%= ddl.ID %>').bind('change',myfunction);

to

$(<%= ddl.ID %>).bind('change',myfunction);

and it started working, any idea ?

EDIT

Sorry Its not working on IE :(

Answer 1

jQuery uses CSS selector like syntax.

For ID Selector it needs to be prefix with # symbol. Example, $('#DOMElementId')

Check jQuery Selector list

In your case correct one should be

$('#<%= ddl.ID %>').bind('change',myfunction) // if you have no master page or 
                                              //ClientIDMode="static"

or

$('#<%= ddl.ClientID %>').bind('change',myfunction)

Answer 2

The jQuery function needs a string as selector.

The latter syntax has no meaning, except

• if your string is a javascript variable (for example document.body or myvar if you defined myvar ).
• if your ddl.ID string contains the quotes (you may have created it as ddl.ID = "\\"#id\\""; )

It's possible you fixed a bug by another bug rendering ineffective this line in your code.

Answer 3

您可能应该改用ClientID

$('#<%= ddl.ClientID %>').bind('change', myfunction);

Answer 4

best option is

$('#'+'<%= ddl.ClientID %>').bind('change',myfunction);

it works even you use this control in user control or content page

$('#'+'<%= ddl.ClientID %>').change(myfunction);