Find previous value of drop down list on change event

Question

I have drop down list declared like :

    <asp:DropDownList ID="myDropDown" width="300" CssClass="textboxda" 
AutoPostBack="True" runat="server" onmousewheel="return false;" />

Drop down list change method

myDropDown.Attributes.Add("OnChange", "return OnChange();");


function OnChange()
{
    var $j = jQuery.noConflict();

    var sel = $j(this).prevAll("#myDropDown:first"),
      val = sel.val(),
      text = sel.find(':selected').text(); 

    alert(text);
}

I am populating this drop down dynamically.

I am fetching the last/previously selected text of the drop down, but this is not working.

Please suggest.

in DOM also I find the same function only...what exactly needed from DOM — Tech, Jun 07 '13 at 07:19

sangram parmar · Accepted Answer · 2013-06-07T08:23:21.620

3

myDropDown.Attributes.Add("OnChange", "return OnChange(this);");

after that you can put another attribute for current selected item

myDropDown.Attributes.Add("previous", "your default selected value");

after that your function like this

function OnChange(args)
{

 var previousVal=$(args).attr('previous');
var newVal=$(args).find(':selected'); 
alert(previousVal);
alert(newVal);
$(args).attr('previous',newVal);
}

edited Jun 07 '13 at 08:23

answered Jun 07 '13 at 07:22

sangram parmar

8,462
2
23
47

It displays like 0.00...I need text...so I made text()...now its showing all items of drop down.. – Tech Jun 07 '13 at 07:28

cetver · Answer 2 · 2013-06-07T07:57:12.387

<select id="countries">
<option value="">Select country</option>
<option value="68">Russia</option>
<option value="20">United States</option>
<option value="73">Albania</option>
<option value="143">Algeria</option>
</select>
<script type="text/javascript">
$(document).ready(function(){
    $('#countries').on('change', function() {
       var $selected = $(this).find(':selected');   
       console.log('Prev = ', $selected.prev().text());
       console.log('Next = ', $selected.next().text());    
       console.log('Last = ', $(this).find('option:last').text()); 
    });
});
</script>

http://jsfiddle.net/S85rY/2/

score 1 · Answer 3 · answered Jun 07 '13 at 08:21

try this

<select id="countries" previous="" onchange="countrychange(this)">
<option value="">Select country</option>
<option value="68">Russia</option>
<option value="20">United States</option>
<option value="73">Albania</option>
<option value="143">Algeria</option>
</select>
<script type="text/javascript">
 function  countrychange(args){
    var previousVal=$(args).attr('previous');
    var newVal=$(args).find(':selected'); 
    alert(previousVal);
    alert(newVal);
    $(args).attr('previous',newVal);
}
</script>

score 0 · Answer 4 · edited Jun 20 '20 at 09:12

0

You want jquery? DEMO http://jsfiddle.net/yeyene/3vRs9/

JQUERY

$(document).ready(function() {        
    $("#mySelect").on('change', function() {
        alert('Changed selected: '+$('#mySelect option:selected').val());   
    });
});

edited Jun 20 '20 at 09:12

Community

1
1

answered Jun 07 '13 at 07:40

yeyene

7,297
1
21
29

This gives the current selection, not what it was prior to being changed – Feuerwehrmann Dec 09 '16 at 16:11

Find previous value of drop down list on change event

4 Answers4

JQUERY