How do I set a value to the Session in asp.net on an onClick event of a normal htmlElement?

Question

I need to make a Function that receives a Session Key and a Session Value and call this function on a normal HTML onClick event. When this function is called the Session variable is assigned the Key I sent with the Value I sent. So far I have this:

<script runat="server" type="text/C#">
        protected void setSessionValue(string key, string value)
        {
            Session[key] = value;
        }  
</script>

But when I try to call if like so:

onclick="setSessionValue('itemID','3345');"

Its not working and giving me an error. Any help? I'm using c# and asp.net but I can't use code behind and need to work everything off the page.

Answer 1

You cannot set anything to the session from the client because session in stored on the server.

Answer 2

You are trying to call the server side (C#, VB.NET) code from the client side (Javascript).

This is not possible.

You can change your HTML control to be server side, by adding the runat="server" attribute on it - you will also need to change the type to one that is recognized serverside, namely <asp:HtmlLink />.

Answer 3

You are trying to invoke a server method from a client side javascript. You can either do as what Oded suggested or, you can use the ASP.NET Ajax to achieve the same.

The below link would be a good starting point on how to do this using ASP.NET Ajax.

ASP.NET Ajax Exposing Webservices to Ajax

Update 1:

Another useful link

Answer 4

Try using

OnServerClick="setSessionValue('itemID','3345');"

instead of

onclick="setSessionValue('itemID','3345');"

Answer 5

Here is a write-up on the difference between Client Side and Server Side ->

Difference between "Client Side" and "Server Side"

Answer 6

Ok I managed to find a solution on my own thanks to all of your submissions, listen to this. I added a javascript function as follows:

function setSessionValue(key, value) {
     $.post('setSession.aspx?key=' + key + '&value=' + value);
}

and added an aspx file with the following code within it:

<%@ Page Language="C#" %>
<% 
    Session[Request["key"]] = Request["value"]; 
%>

Basically this worked just fine, all I needed was a little jQuery. Thanks to all for your suggestions.