CH13: LINQ and the bulleted list

sabarnett · January 27th, 2010, 07:09 AM

Had no problem getting the bulleted list displayed from Chapter 13, but wanted to extend it a little. The idea was to turn the listitems in to links so I could create a "details" page for the user.

I changed the bulleted list definition to:

Code:

        <asp:BulletedList ID="lstReviews" runat="server" 
            DataSource='<%# Eval("Reviews") %>' DataTextField="Title" 
            DisplayMode="HyperLink" DataValueField='Id' 
            BulletStyle="Disc" >

which correctly converts the items to links. Problem is, this gives me links like:

localhost/Site/Reviews/17

where "17" is ths id from the record. What I need to do is inject some additional information to turn this in to

localhost/Site/Reviews/ReviewDetail.aspx?Id=17

Nothing I've tried has got me anywhere.

Any suggestions as to how I can achieve this please?

I've tred adding code to the DataValueField in the bulleted list and have tried to define a field in the LINQ statement - but that won't work because I have no direct access to add fields to the Reviews collection.

Thanks
Steve

barakros · January 27th, 2010, 08:10 AM

http://weblogs.asp.net/atlaszhu/arch...a-binding.aspx

it seems there is no easy way for that with bulletslist
but maybe I am wrong...

Barak

but...
you can replace the bulletlist with datalist:

Quote:

<asp:DataList ID="rptLetters" runat="server" DataSource='<%# Eval("Reviews")%>'>
<ItemTemplate>
<asp:HyperLink ID="cmdLetter" runat="server"
NavigateUrl='<%#GetLink(Eval("id"))%>'
Text='<%#Eval("Title")%>' />
</ItemTemplate>
</asp:DataList>

and in code behind:

Quote:

Protected Function GetLink(ByVal aId As Integer) As String
Return "~/Reviews/ReviewDetail.aspx?id=" & aId
End Function

that will work but you won't have the bullets :)

sabarnett · January 27th, 2010, 09:23 AM

Excellent, thank you.

I did look at that article on bulleted lists, but it seemed horribly complicated for such a simple requirement. The DataList seems much more sensible.

I'm not particularly bothered by the bullet point itself and can probably insert that using a little css code. If I generate myself a class with a background image (non-repeating) and a left margin - so the text appears to the right of the image, I'm sure I can make a credible looking bullet point.

Many thanks
Steve

Imar · January 27th, 2010, 09:32 AM

Instead of a DataList, you can also use a Repeater. Put the <ul> and </ul> in the HeaderTemplate and FooterTemplate respectively, and add <li> elements to the ItemTemplate. That way, you have full control over the markup.

Hope this helps,

Imar

sabarnett · January 27th, 2010, 12:43 PM

Thanks Imar, I'll give that a try too.... it's all good learning, after all.

I think I became far too focussed on the example in the book when I should have just been playing around.

Steve

sabarnett · January 27th, 2010, 05:05 PM

On the off-chance that anyone else if following along, this is what I ended up with:

Code:

    <asp:Repeater ID="repReviews" runat="server">
    <ItemTemplate>
        <h3><asp:Literal ID="itemTitle" runat="server" Text='<%# Eval("Name") %>' /></h3>
        <asp:Repeater ID="lstGroups" runat="server"  DataSource='<%# Eval("Reviews") %>' >
            <HeaderTemplate><ul></HeaderTemplate>
            <ItemTemplate>
                <li>
                    <asp:HyperLink ID="cmdReview" runat="server" 
                            NavigateUrl='<%# GetUrl(Eval("Id")) %>' 
                            Text='<%# Eval("Title") %>' />
                </li>
            </ItemTemplate>
            <FooterTemplate></ul></FooterTemplate>
         </asp:Repeater>
    </ItemTemplate>
    </asp:Repeater>

and in the code behind:

Code:

    protected void Page_Load(object sender, EventArgs e)
    {
        using (PlanetWroxDataContext myReviews = new PlanetWroxDataContext())
        {
            var allGenres = from revs in myReviews.Genres
                            orderby revs.SortOrder
                            select new { revs.Name, revs.Reviews };
            repReviews.DataSource = allGenres;
            repReviews.DataBind();


        }
    }

    public string GetUrl(object Id)
    {
        return String.Format("~/Reviews/ReviewDetail.aspx?Id={0}", Id.ToString());
    }

Thanks for the help.

Steve

Imar · January 27th, 2010, 06:54 PM

Now that you're using the Repeater, you can drop the method in code and use this instead:

Code:

 
<asp:HyperLink ID="cmdReview" runat="server" 
    NavigateUrl='<%# "~/Reviews/ReviewDetail.aspx?Id=" + Eval("Id").ToString() %>' 
    Text='<%# Eval("Title") %>' />

Just a matter of preference, though....

Imar