WPF tab control and MVVM selection

Question

I have a TabControl in an MVVM WPF application. It is defined as follows.

Answer 1

The accepted answer is not working with DependencyObject on your ViewModel .

I'm using MVVM with DependencyObject and Just setting the TabControl didn't work for me.The problem I had was the the property was not getting update on the View when I was setting the tab selectedIndex from the ViewModel.

I did set the Mode to be two ways but nothing was working.

    ...

The ViewModel property "SelectedTab" was getting updated all the time when I navigated between tabs. This was confirming my binding was working properly. Each time I would navigate the tabs both the Get and Set would get called in my ViewModel. But if I try to set the SelectedIndex in the ViewModel it would not update the view. ie: SelectedTab=0 or SelectedTab=1 etc... When doing the set from the ViewModel the SelectedTab 'set' method would be called, but the view would never do the 'get'.

All I could find online was example using INotifyPropertyChanged but I do not wish to use that with my ViewModel.

I found the solutions in this page: http://blog.lexique-du-net.com/index.php?post/2010/02/24/DependencyProperties-or-INotifyPropertyChanged

With DependencyObject, you need to register the DependencyProperties. Not for all properties but I guess for a tabcontrol property you need to.

Below my code:

view.xaml

//Not sure below if I need to mention the TwoWay mode

        ...

ViewModel.cs

public class ViewModel : DependencyObject
{
       public static readonly DependencyProperty SelectedTabDP =  DependencyProperty.Register("SelectedTab", typeof(int), typeof(ViewModel));

       public int SelectedTab
       {
          get { return (int)GetValue(SelectedTabDP); }
          set { SetValue(SelectedTabDP, value); }
       }
}

Basically all I had to do was to actually register the dependency property (DependencyProperty) as you can see above.

What made this hard to figure out was that I have a bunch of other Properties on that view and I didn't need to register them like that to make it work two ways. For some reason on the TabControl I had to register the property like I did above.

Hope this help someone else.

Turns out my problem were because my components have names:

x:Name="xxxxxxxx"

Giving names to components at the same time of biding them with DependencyObject seems to be the main cause of all my issues.