I have been working with master pages for a very short time, so I apologize if this is a simple question.

I am creating a content page that will (in theory) use one of multiple master pages available through my web site. The PreInit method seems to easily handle this change:

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
   Me.MasterPageFile = "~/Master_Pages/MinimalLayout.master"
End Sub

The issue I am running into right now is that I am unclear on how to get the page to show the default content from each master page when dynamically changing the master file. Each master file has a varying number/position/style of placeholders, so I would ideally like to be able to populate the content in a dynamic fashion. I tried adding the content control(s) in preinit and associating them to each master placeholder, but I get an error message that says this:

Setting the ContentPlaceHolderID property of System.Web.UI.WebControls.Content is not supported.

here's the code I tried; the intial call in PageInit is AddPlaceholderControls(Me.Master):

Private Sub AddPlaceholderControls(ByVal oParent As Control)

   Dim oContent As Content

   For Each oCtl As Control In oParent.Controls
      
      If TypeOf oCtl Is ContentPlaceHolder Then
         oContent = New Content
         With oContent
            .ContentPlaceHolderID = oCtl.ID
         End With
         Me.Controls.Add(oContent)

      ElseIf oCtl.HasControls Then
         AddPlaceholderControls(oCtl)
      End If

   Next

End Sub

Any assistance or direction would be greatly appreciated!

Why not just have the ID of the ContentPlaceHolder the same across both MasterPages?   then when your aspx page says: "go fill Content Place Holder 'Holder1' with this stuff", it doesn't matter what MasterPage it is

Good point... and yes, that will work. I'm thinking more from the perspective of having varying/multiple placeholders, depending on the master page. The way it's set up right now I don't think that I would be able to do this without having an aspx page for each template. Seems like this defeats part of the intent of master pages...?

jatfill wrote:

Seems like this defeats part of the intent of master pages...?

Just my 2 pennies:

I don't agree with that thinking, as the MasterPage is a design structure that is independant of the content

Like the setup i have is one single set of code pushing out content/functionality to two different websites/urls, same site, different look (which sounds like what you are after with a master page called "MinimalLayout" (maybe i'm wrong though)

If the content does vary based on master page, i'd go about using User Controls for the content and dynamically load them based on whatever criteria is deciding your master page

Hi

Having exactly the same problem, and I have to load the Content dynamicly, as I use many different MasterPages with different numbers of PlaceHolders...

Have you found a solution on this problem or just using the "work around" descriped bellow...?

Same problem!!

And almost a year and a half after,......

ContentPlaceHolder myContent = (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");

Label

myLabel = new Label();

myLabel.Text =

"Hello over a year after your question, and even though I don´t know whether this will answer it!!";

myContent.Controls.Add(myLabel);