MasterPages 继承另一个 MasterPage

Question

I am working on a website that has many MasterPages and one of them inherits from another master page and I am trying to add a control to the parent masterpage like this

myMasterPage.Page.Controls.Add(new LiteralControl(theSuperStoreString.ToString()));

But I get the following error

The control collection cannot be modified during DataBind, Init, Load, PreRender or Unload phases.

How can i do this?

Thank you

Answer 1

First of all you should never add any control to your parent control. It violates separation of concerns principle, breaks integrity and is the first sign of bad design (and troubles in the project).

If you have to modify Controls of your parent or another control use event, state property or interface to delegate this request to the object which is really responsible for it (parent MasterPage in that case).

Regarding to your question place a control in your parent MasterPage and show it only when someone request for it.

Answer 2

I think you are trying to add the control too late in the cycle, try the preinit event

added as I read your comment

here is a link to the lifecycle

http://msdn.microsoft.com/en-us/library/ms178472.aspx

so essentially what we are saying is you need to overrid ethe preinit event and add/create new controls there rather than the later events (where it seems you are currently trying to add)