How could you enable a WPF application to create user controls on the fly?

Question

How could you create an application that could search through a directory, find user controls in the form of paired .xaml / .xaml.cs files, and compile/execute these on the fly? Is this possible? Is there an .exec() or .compile() class somewhere that could do this?

Basically what I want to do with this is have a WPF application that is running and by having the user fill out a form describing the kind of page/functionality he wants, the application could generate XAML and code behind files which are then immediately usable without having to recompile the application.

Answer 1

Is this a good idea? I can see a few problems with this.

1. How will the code behind 'know' how to interact with the rest of the application
2. Security? You will be allowing somebody to make system API calls on behalf of the main application
3. App domains???

Rather build up the forms using ItemsControls and DataTemplates. In the form where the user specifies what functionality he wants in the form, you will be presenting him with a list of 'building blocks' anyway. Make each 'building block' a ViewModel and associate each ViewModel with a DataTemplate 'UserControl'.

Answer 2

I'm assuming that this is to change the behaviour of the UI on a known application rather than a XAML/CS component generator for use in another application - after all there's already applications that do this - Expression Blend anyone?

Do you really need to recompile the underlying CS? As far as I can see it all you'll be doing is changing the apparent behaviour and look of the application and UI. This could be achieved by command binding within the xaml and styles for the components.

The reality is that in order to perform the functionality that you require you'll be giving the user a finite choice as to behaviour. You'll need to decide what behaviour is application and what is the UI.

Application bahaviour is governed by fixed commands (they could accept parameters to change behaviour).

UI behaviour (appearance, animation etc) is covered by the xaml. If the application runs in a browser window you could auto generate the xml needed as requried, linking it to the underlying app. commands and allow the browser to execute the new behaviour for you.