Divide By Zero - a blog by Kamran Ayub

Solution

How do you fix it? I found a great post on how to nest the sitemap in a master-detail style and then adjust the parent node's URL, but I wanted to actually add a new node because I was viewing and listing news on the same page.

Here's how you do it:

Private _mHeadline as String = String.Empty

Sub Page_Load(sender as object, e as eventargs) handles me.load

	' Here you set the page title to whatever dynamic thing
	' you're loading.
	_mHeadline = "A test"

	AddHandler SiteMap.SiteMapResolve, AddressOf SiteMapResolve

End Sub

Protected Sub Page_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Unload
        ' Remove this specific handler once the page is done.
        ' Otherwise it will get called on other pages.
        RemoveHandler SiteMap.SiteMapResolve, AddressOf SiteMapResolve
End Sub

Protected Function SiteMapResolve(ByVal sender As Object, ByVal e As SiteMapResolveEventArgs) As SiteMapNode

        Dim cn As SiteMapNode = SiteMap.CurrentNode.Clone(True)
        Dim newNode As SiteMapNode

	' "viewnews" can be changed to whatever you want. It's just a key.
        If _mViewTitle <> String.Empty Then
            newNode = New SiteMapNode(SiteMap.Provider, "viewnews", Request.Url.PathAndQuery, _mHeadline)
            newNode.ParentNode = cn
        Else
            newNode = cn
        End If

        Return newNode
End Function

So I left out how I was getting the title of the news headline because I assume you know how to do that. The place that is interesting is the SiteMapResolve function. I create a new node and set its parent to the current node, which successfully has the SiteMapPath show the correct breadcrumb:

Home > News > A headline!

A couple notes:

First, I remove the handler once the page is complete because otherwise the function will get called every time the SiteMap resolves itself, which is not what we want!

Second, you may need to touch the web.config (just remove a line and undo it) and save it to have your application recycle itself, otherwise your changes might not show up.

Hope this helps somebody.