Is it a good idea to aggregate ViewModels?

Question

Is it a good or bad idea to have a ViewModel as a property of another ViewModel?

For example:

public sealed class ContentManagerViewModel : ViewModel
{
    public FindViewModel Find { get; set; }
}

Answer 1

It's good, if it helps. But it all depends.

Usually I do have aggregated viewmodels. E.g. I may have a main window viewmodel. It may consist of different parts. Each part may be a separate view model...

If you could describe your particular architecture, we may give better advice :)..

Cheers, Anvaka

Answer 2

Aggregate ViewModels you do only having relations between them. If thats the case you should better use the Mediator pattern with a concrete Messaging System.