passing variable to javascript function fails in asp:dropdownlist

Question

Currently I have a function called in the following way:

<script type="text/javascript">
getCities('<%=BusinessID %>');
</script>

This works without any problem, now I want to do the same on an onchange event in a asp:dropdownlist as following:

<asp:DropDownList ID="ddlAddressSPC" runat="server" clientidmode="Static" AutoPostBack="False" onchange="javascript:getCities('<%=BusinessID %>');" Width="306px" CssClass="txt12NormalLeft" ToolTip="Select State|Province|County" />

But now the ASP.net variable isn't evaluated and is passed as <%=BusinessID %> instead of the value.

If I do the same code in a normal HTML select it isn't a problem. What am I missing here?

That puts the text <%=BusinessID %> inside the variable, I want to have the value of BusinessID in there, my function is in an external js file. — Gerard van den Bosch, Oct 06 '14 at 12:04

score 1 · Answer 1 · edited May 23 '17 at 11:46

1

This should work.

<script type="text/javascript">

var currentBusinessIdString = '<%=BusinessID %>';

var currentBusinessId = parseInt(currentBusinessIdString);

getCities(currentBusinessId);

</script>

If this didn't help you, you may try some issues listed here : How do I give JavaScript variables data from ASP.NET variables?

edited May 23 '17 at 11:46

Community

1
1

answered Oct 06 '14 at 12:20

Razvan Dumitru

11,815
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score 1 · Accepted Answer · answered Oct 06 '14 at 12:22

1

You can't do that directly at the server element tag.

You should do that somewhere in the code behind:

ddlAddressSPC.Attributes.Add("onchange", "javascript:getCities('" + BusinessID + "');");

answered Oct 06 '14 at 12:22

Luizgrs

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score 1 · Answer 3 · answered Oct 06 '14 at 12:22

try like this

Remove this from markup

onchange="javascript:getCities('<%=BusinessID %>');"

and add in page_load

 protected void Page_Load(object sender, EventArgs e)
  {

      ddlAddressSPC.Attributes.Add("onchange", "getCities('" + BusinessID + "')");
  }

passing variable to javascript function fails in asp:dropdownlist

3 Answers3