Make Panel visible with Hyperlink

Filespit · August 1st, 2010, 01:19 PM

Hi!

Is it possible to make a Panel visible by clicking on a Hyperlink? I know this works well with RadioButtonLists, but cannot figure out if it works with Hyperlinks. If yes, what to I write? I am using Visual Basic.

Cheers
Peter

Imar · August 1st, 2010, 03:45 PM

You could. However, since HyperLink render as a client side link, you need to pass some state in the URL that tells the panel to hide itself when the page gets requested. E.g.:

SomePage.aspx?HidePanel=True

Then in SomePage.aspx, you access Request.QueryString.Get("HidePanel") and when it contains the value True, you hide the panel.

However, if it's appearance (e.g. text that looks like a link) rather than behavior (e.g. a HyperLink versus another control), I think you're better off using a LinkButton. At the client, it looks like a HyperLink, but it submits back to the server (to the page where it's used) where you can handle its Click event and hide the Panel.

Hope this helps,

Imar

Filespit · August 2nd, 2010, 11:42 AM

Hi!

Does this mean I need to have another page with data that loads inside the Panel, like an iframe, or have I misunderstood? Otherwise it sounds like a LinkButton is a better alternative. The way I understand your description is that a LinkButton is a "fake" hyperlink that loads a Panel when you click on it. If so, that's what I was looking for.

Cheers
Peter

Imar · August 2nd, 2010, 11:49 AM

You misunderstood. a HyperLink simply ends up as a <a href /> element in the browser. By linking it to the same page, with HidePanel=True in the query string you can reload the page and hide the panel. However, indeed you probably want a LinkButton. It also ends up as an <a href /> but uses JavaScript to post back to the same page.

Cheers,

Imar

Filespit · August 10th, 2010, 10:08 AM

Hello again,

I inserted a LinkButton in my page with a PostBackUrl;

Code:

<asp:LinkButton ID="LinkButton" runat="server" PostBackUrl="SomePage.aspx">Link</asp:LinkButton>

Then in my CodeBehind i wrote;

Code:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

Panel.Visible = False

If LinkButton.OnClientClick Then
    Panel.Visible = True
End If

With this I get an error message saying the "in-data-string had an incorrect format". What do I need to do, or did I write the wrong script?

Cheers
Peter

Imar · August 10th, 2010, 10:16 AM

You're mixing up lots of stuff.

First, remove the PostBackUrl property. Then double click the LinkButton in design view to set up a *server side* Click handler. Inside that method, hide the panel.

This all assumes the Panel and LinkButton are in the same page.

OnClientClick is a property that is used to assign a client side JavaScript function that is triggered when the link button is clicked at the client; e.g. before the post back.

Hope this helps,

Imar

Filespit · August 10th, 2010, 10:36 AM

I see now what I did wrong, that worked perfectly!

Though, I am making the Panel visible inside the method, as I want it to be invisible from the start. But either way it works perfectly.

Thanks for the help!