移动到JavaScript .js文件时，C＃的嵌入式服务器代码无法工作

Question

Within my C# code behind page, I have the following:

MembershipUser currentUser = Membership.GetUser(false);

HttpContext.Current.Session["UserGuidAsString"] = currentUser.ProviderUserKey.ToString();

At the bottom of the corresponding ASPX page, I have the following code:

</form>
<script type="text/javascript"> var userGuidAsString = '<%=Session["UserGuidAsString"]%>';
                                alert(userGuidAsString);
</script>
</body>
</html>

It gives the proper expected result which is an alert box with the User's GUID when I run the page

I wanted to move the JavaScript code to a .js file so that the code is more modularized and organized. I created the following test.js javascript file with the following contents:

var userGuidAsString = '<%=Session["UserGuidAsString"]%>';
alert(userGuidAsString);

I also modified the ASPX page so that it would include the test.js javascript file:

</form>
    <script src="/Scripts/test.js" type="text/javascript"></script>
    </script>
</body>
</html>

It fails because it just gives an alert box with '<%=Session["UserGuidAsString"]%>' as a message

May I please know how I can make in line server C# code work within JavaScript .js files?

Answer 1

By This your accessing Server Variable

'<%=Session["UserGuidAsString"]%>'

its not functionlity of Javascript.

You can write this code without js block also.. its like ASP code.. so its workg with .aspx page only not in javascript

Answer 2

A common workaround for this is to put the server variable in an html hidden element. For example:

<input type="hidden" id='guid' value='<%=Session["UserGuidAsString"]%>' />

Then your javascript file:

var guid = document.getElementById("guid").value;

Or , you could define a js variable in your html, and reference that in your js file. Just make sure to declare the variable before you reference it.

<script type="text/javascript">
    var guid = '<%=Session["UserGuidAsString"]%>';
</script>
<script type="text/javascript" src="yourScript.js></script>

Then in your js file you can simply use the guid variable.

Answer 3

In order for C# to get executed on the server before the .js file reaches the client, you'd have to register that page extension in IIS so that the asp_net .dll processes .js files.

In your particular case (handling GUIDs), you really don't want to go this route, because with the nature of .js file caching, you're going to have a lot of problems ensuring that it's a fresh version being served up every time.

I suggest recreating a very simple (and yes, modular/reusable) JS function that makes a call to, say, GetUserGuidAsString.aspx by using AJAX or the equivalent.