MVVM Binding - creating a control in a View, how bind to property in ViewModel?

Question

We add tabcontrols to our application at runtime. Each tabcontrol is given a ViewModel as a DataContext. We add the tabcontrols by sending a message to the main app View; the message contains the ViewModel to be used as datacontext.

From the main app ViewModel, we add tabitems to the tab controls by sending a message to the main app view to create a TabItem and add it to the specified TabControl.

I'd like to bind certain properties of the TabItem to certain properties of the TabControl's ViewModel; this needs to be done programmaticaly, of course.

Since the tabcontrol and tabitem don't know about ViewModels (only DataContext), how do I specify the properties of the ViewModel to bind the tabitem properties too?

Thanks for any advice...

    Messenger.Default.Register<AddTabControlMessage>(this, m =>  
    {
     TabControl tc = new TabControl();
     tc.DataContext = m.ViewModel;
     // etc.
    } );

Nick Heidke Nick Heidke · Accepted Answer · 2011-07-01T16:25:05

You can cast the DataContext to the type of the ViewModel and then access the properties that way.

tc.SomeProperty = ((MyViewModel)DataContext).SomeVMProperty;

MVVM Binding - creating a control in a View, how bind to property in ViewModel?

1 Answers