Category: JavaScript

31 Mar 2016 01:10

Joined:	05/02/2011
Level:	Silver
Points:	102

Points:	5

How to javascript function from dropdownlist?

I have javscript function which I want to call from dropdownlist.If I call javascript function from onchange event of dropdownlist from page_load,my dropdownlist's selectedIndexchanged event does not fire.How to handle it?.I want to call both javascript function and selectedindexchanged from dropdownlist.

//Javascript
<script language="Javascript" type="text/javascript">
function()
{
}
</script>

//Page_load()
ddlSubject.Attributes.Add("onchange", "return CallSubject()");
//

protected void ddlSubject_SelectedIndexChanged(object sender, EventArgs e)
{

}
Suppose I have button control and want call javascript function from button.I will call javascript function from button's onclientclick event,after that my button's click event fire.I want like that in dropdownlist.

#765329

31 Mar 2016 03:19

Joined:	13/01/2015
Level:	Silver
Points:	230

Points:	1

You need to set :
AutoPostBack="true"
for the drop down.

It will surely work.
(Y)

Thanks!
Anjali Bansal

~Give your best and lead the world

#765331

31 Mar 2016 05:38

Joined:	31/03/2016
Level:	Bronze
Points:	9

Points:	4

<select id="myList" >
<option id="stylesheet1" value="default">Default</option>
<option id="stylesheet2" value="one">Theme 1</option>
<option id="stylesheet3" value="two">Theme 2</option>
<option id="stylesheet4" value="three">Theme 3</option>
</select>

document.getElementById("myList").onchange = function() {
var sheet=document.getElementById("myList").value;

if(sheet=="one"){
setActiveStyleSheet("theme1");
}
else if(sheet=="two"){
setActiveStyleSheet("theme2");
}
else if(sheet=="three"){
setActiveStyleSheet("theme3");
}
else{
setActiveStyleSheet("default");
}
return false
};

#765334

31 Mar 2016 06:18

Joined:	15/12/2015
Level:	Gold
Points:	1308

Points:	3

Hi,
Add this line inside Page_Load():
{
ClientScript.GetPostBackEventReference(this, string.Empty);
}
ASPX Page:
function abc()
{
__doPostBack('<%= YourDropDown.ClientID %>', '');
}
<asp:DropDownList runat="server" ID="YourDropDown" onchange="javascript:return abc();" OnSelectedIndexChanged="Unnamed_SelectedIndexChanged"></asp:DropDownList>
Hope it helps.
Regards,
Shashikant Gurav
shashikantgurav22@gmail.com

#765752

30 Apr 2016 07:46

Joined:	21/10/2009
Level:	Gold
Points:	1518

Points:	4

Hi

by the code ddlSubject.Attributes.Add("onchange", "return CallSubject()"); you are assigning event to ddlSubject dropdown but you are not calling the function .

to call a script inside server side function we need server startup in out code then only we can call client side script inside the server side .

Eg definition of script
function CallSubject() {
alert("hello!")
}

inside onload of server side or in any event call we need to code like this to call client side function

ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "text", "CallSubject()", true);

ScriptManager.RegisterStartupScript -- > which use to call the client side function in server side
"text" is the name you can give any name for that script we mention
CallSubject() : where we call our exact client side function

#765764

02 May 2016 02:42

Joined:	13/06/2007
Level:	Gold
Points:	21327

Points:	2

onchange event is from client side and on_selected index change is from server side, first onchange event gets triggered if it returns TRUE then it automatically call selectedIndexChanged otherwise it won't.
basically you need to keep 'autopostback' property of dropdown list set to 'true'

Thanks
Koolprasd2003
Editor, DotNetSpider MVM
Microsoft MVP 2014 [ASP.NET/IIS]

How to javascript function from dropdownlist?

About dotnetspider.com

Quick Links

General

Services