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How can I bind a CommandParameter with a child UserControl's child element?

I have the following xaml view:
<UserControl x:Class="MyViews.PersonView"
xmlns:views="clr-namespace:MyViews"
[...]
>
[...]
<dxb:BarManager x:Name="MainBarManager">
<dxb:BarManager.Items>
<dxb:BarButtonItem x:Name="bbiPrint"
Content="{Binding Print, Source={StaticResource CommonResources}}"
Command="{Binding PrintPersonsCommand}"
CommandParameter="{Binding PersonsCardView, ElementName=CardUserControl}"
/>
</dxb:BarManager.Items>
<Grid>
<Grid.RowDefinitions>
[...]
</Grid.RowDefinitions>
<views:CardView x:Name="CardUserControl" Grid.Row="2"/>
</Grid>
[...]
</UserControl>
The CardView is defined as follows:
<UserControl x:Class="MyViews.CardView"
[...]>
[...]
<dxg:GridControl ItemsSource="{Binding Persons}" SelectedItems="{Binding SelectedPersons}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" SelectionMode="MultipleRow">
[...]
<dxg:GridControl.View>
<dxg:CardView x:Name="PersonsCardView"
[...]
CardTemplate="{StaticResource DisplayCardTemplate}"
PrintCardViewItemTemplate="{StaticResource PrintCardTemplate}"/>
</dxg:GridControl.View>
[...]
</dxg:GridControl>
</UserControl>
The PrintPersonsCommand is defined as follows in my ViewModel:
public class PersonViewModel
{
public PersonViewModel(...)
{
[...]
PrintPersonsCommand = new Prism.Commands.DelegateCommand<DataViewBase>(PrintPersons, CanPrintPersons);
}
public Prism.Commands.DelegateCommand<DataViewBase> PrintPersonsCommand { get; private set; }
private void PrintPersons(DataViewBase view)
{
_printService.ShowGridViewPrintPreview(view);
}
private bool CanPrintPersons(DataViewBase view)
{
return true;
}
}
Now, when I click the Print button, the above PrintPersons method is always fed with null. How do I pass CardUserControl.PersonsCardView in my MyViews.PersonView xaml above, how do I pass that PersonCardView to my command? In other words, how do I fix
CommandParameter="{Binding PersonsCardView, ElementName=CardUserControl}"
to make it work?
Currently, the only solution I've found to this problem is to replace the Command and CommandParameter with
ItemClick="OnPrintBtnClick"
and then in the PersonView's code-behind file to do:
private void OnPrintBtnClick(object sender, ItemClickEventArgs e)
{
var ctxt = DataContext as PersonViewModel;
ctxt.PrintPersonsCommand.Execute(CardUserControl.PersonsCardView);
}
That works but I can't believe there is no other way. I'm not happy with that solution because I don't have the benefits of using the Command any more, like e.g. the automatic evaluation of the Command's CanExecute method. I could also put the CardView's xaml code in the PersonView.xaml but I like my controls to be in separate files because I have the feeling it's more structured and each user control has its own responsibilities which can nicely be split into separate files. Also, that solution binds my view to my view model too tightly.
Can someone help me out please?

Without changing your existing view and viewmodel hierarchy, I was able to pass the GridControl.View to the PersonViewModel using the Tag property
You can assign the CardView to the Tag property at the bottom of your CardView UserControl, and then access this Tag as CommandParameter.
CardView UserControl
<UserControl x:Class="MyViews.CardView"
[...]>
[...]
<dxg:GridControl ItemsSource="{Binding Persons}" SelectedItems="{Binding SelectedPersons}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" SelectionMode="MultipleRow">
[...]
<dxg:GridControl.View>
<dxg:CardView x:Name="PersonsCardView"
[...]
CardTemplate="{StaticResource DisplayCardTemplate}"
PrintCardViewItemTemplate="{StaticResource PrintCardTemplate}"/>
</dxg:GridControl.View>
[...]
</dxg:GridControl>
<UserControl.Tag>
<Binding ElementName="PersonsCardView"/>
</UserControl.Tag>
</UserControl>
Print Button Xaml:
<dxb:BarButtonItem x:Name="bbiPrint"
Content="{Binding Print, Source={StaticResource CommonResources}}"
Command="{Binding PrintPersonsCommand}"
CommandParameter="{Binding ElementName=CardUserControl, Path=Tag}"
/>

Based on the valuable input of Insane, I came up with the following two cleaner fixes:
Code-behind solution
In the PersonView, use the ItemClick event handler on the Print button:
<dxb:BarButtonItem x:Name="bbiPrint"
Content="{Binding Print, Source={StaticResource CommonResources}}"
ItemClick="OnPrintBtnClick"/>
Adapt the corresponding code-behind file like this:
public partial class PersonView : UserControl
{
readonly IPrintService _printService;
public PersonView(IPrintService printService)
{
_printService = printService;
InitializeComponent();
}
private void OnPrintBtnClick(object sender, ItemClickEventArgs e)
{
_printService.ShowGridViewPrintPreview(CardUserControl.PersonsCardView);
}
}
Because I want to gray-out the Print button when there is no selection, I still need to add some code to make that happen. I can get it by
1. updating the button code to
<dxb:BarButtonItem x:Name="bbiPrint"
Content="{Binding Print, Source={StaticResource CommonResources}}"
ItemClick="OnPrintBtnClick" IsEnabled="{Binding CanPrintPersons}"/>
refreshing the CanPrintPersons property in the PersonViewModel upon Persons selection change
That's it.
CardViewModel solution
In that solution, we have a PersonView with its underlying PersonViewModel and a CardView with its underlying CardViewModel. I will not describe that solution with all the details as it is overkill in my situation but for the sake of completeness, I'll give the main points. Upon clicking the Print button on the PersonView, the PersonViewModel's PrintCommand is called. That command emits a Print event to the CardViewModel which in turn calls its own PrintCommand. That latter command calls
_printService.ShowGridViewPrintPreview(View);
where the View is a CardViewModel's property that is set upon CardView loading with e.g.
<dxmvvm:Interaction.Behaviors>
<dxmvvm:EventToCommand EventName="Loaded" Command="{Binding ViewLoadedCommand}" CommandParameter="{Binding ElementName=PersonsCardView}" />
</dxmvvm:Interaction.Behaviors>
Because I have two child views I want to print, I'd need to add a view model for each one of those. In addition, those two view models plus the PersonViewModel need access to the list of Persons to be printed. In particular, they need a shared access to the same data, so that they are synchronized. A simple way to do that is explained here and is totally doable. But I think it is not worth the trouble for the simple use case I have as it adds more complexity than necessary.

Windows 10 Universal Compiled binding (x:Bind) conflict with ViewModel

I want to bind an element in a page to dependency property in code behind with compiled binding and same time bind another element to ViewModel with usual binding. But it gives a runtime error.
Here is my xaml code.
<Page
x:Class="XbindingProblem.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XbindingProblem"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
DataContext="{Binding Main, Source={StaticResource Locator}}"
mc:Ignorable="d">
<Page.Resources>
<DataTemplate x:Key="UserDataTemplate" x:DataType="local:User">
<StackPanel>
<TextBlock Text="{x:Bind Name}" />
<TextBlock Text="{x:Bind Age}" />
</StackPanel>
</DataTemplate>
</Page.Resources>
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel>
<TextBlock Text="{Binding Title}"/>
<ContentPresenter ContentTemplate="{StaticResource UserDataTemplate}" Content="{x:Bind CurrentUser, Mode=OneWay}"/>
</StackPanel>
</Grid>
Here CurrentUser is dependency property which is initially null and then change in run time. This gives following runtime error.
Incorrect type passed into template. Based on the x:DataType global::XbindingProblem.User was expected.
The problem is it passes the ViewModel into UserDataTemplate instead of CurrentUser dependency property when CurrentUser is null.
Can anyone have a good explanation on this problem?

If you remove DataContext="{Binding Main, Source={StaticResource Locator}}", it will work. Why? because {x:Bind CurrentUser} is looking for a property called CurrentUser sitting inside your MainPage.xaml.cs. Since the CurrentUser is indeed a dependency property of your page, it will just work.
However, by specifying the DataContext of your page, the x:Bind is now excepting a CurrentUser property inside your MainViewModel instance, and of course it's not going to find it, so a compile-time error will be thrown.
One possible fix is to set the this.CurrentUser really early, even before calling InitializeComponent.
this.CurrentUser = new User();
InitializeComponent();
But this is IMHO not the the right way of doing things, as it's basically a racing game - it tries to populate the ContentPresenter before the DataContext gets updated, and in the end you will end up having the TextBlock (of which Text binds to Title) and the ContentPresenter attached to different contexts!
So ask yourself why you need to create a dependency property for CurrentUser inside a Page object, instead of having a normal property (with INotifyPropertyChanged implementation) sitting inside your MainViewModel? I'd prefer the latter, 'cause it's more semantically correct.

The question is interesting, what I have done is just remove the datacontext and this is the code behind is similar to yours:
public sealed partial class BlankPage1 : Page
{
public User CurrentUser
{
get { return (User)GetValue(CurrentUserProperty); }
set { SetValue(CurrentUserProperty, value); }
}
// Using a DependencyProperty as the backing store for CurrentUser. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CurrentUserProperty =
DependencyProperty.Register("CurrentUser", typeof(User), typeof(BlankPage1), new PropertyMetadata(null));
public BlankPage1()
{
this.InitializeComponent();
CurrentUser = new User() { Name = "Hello", Age = "20" };
}
}
public class User
{
public String Name { get; set; }
public String Age { get; set; }
}
might be you have the User class in another namespace or have another class in the typeof(...) of the dependency property. Because I tested that and works. The DataContext of the page can be whatever you want it won't affect.
Then I added the datacontext just to test:
<Page.DataContext>
<local:Main/>
</Page.DataContext>
and the code just for testing:
public class Main
{
public String Title { get; } = "title";
public User MainUser { get; set; }
}
And it does not throws any exception, appears the Main data and the CurrentUser data.
UPDATE. The error happens when the User is null so it is like the x:Bind is null it propagates to the Binding,To solve that (it was tough):
<Page x:Name="Root"
x:Class="Deletetb.BlankPage1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Deletetb"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" >
<Page.DataContext>
<local:Main/>
</Page.DataContext>
<Page.Resources>
<DataTemplate x:Key="UserDataTemplate" x:DataType="local:User">
<StackPanel>
<TextBlock Text="{x:Bind Name}" />
<TextBlock Text="{x:Bind Age}" />
</StackPanel>
</DataTemplate>
</Page.Resources>
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel DataContext="{x:Null}">
<TextBlock Text="{Binding DataContext.Title, ElementName=Root}" />
<ContentPresenter ContentTemplate="{StaticResource UserDataTemplate}" Content="{x:Bind CurrentUser, Mode=OneWay}"/>
</StackPanel>
</Grid>
</Page>
Where is binding defined (TextBlock) I set the datacontext to null in the parent container (StackPanel) and bind by element name, and it does not crash, also I added a wait by code to test and set the Current User and it works. That was a challenge. hope it also works for you.

Although it breaks the idea of MVVM a bit, you can add a property to your page like this:
public MainViewModel viewModel => DataContext as MainViewModel;
And then in the XAML code reference the page property
<ContentPresenter Content="{x:Bind viewModel.CurrentUser, Mode=OneWay}" />

WPF window not updating with binding in XAML

Can someone please explain what's going on here? I'm new to WPF and migrating my Forms project to WPF with binding. I'm using AvalonDock but I'm not binding directly to any of the AvalonDock controls. Here's a couple excerpts. I removed a lot for brevity's sake but let me know if you need to see something else.
EDIT: These two StackPanels are just tests... trying to figure this stuff out.
EDIT2: I'm trying to do MVVM eventually; I just need to get a better handle on binding so I know how to structure it.
EDIT3: See bottom of post.
Q: The first StackPanel does not update at all, never mind updating after changes. I've tried setting the DataContext in the StackPanel, Grid and TextBlock. What am I doing wrong?
Q: The second works fine when the parent grid is bound in code behind but only if bound where you see it, not in the MainWindow_Loaded() method. What's different here?
I've read several tutorials as well as plenty of similar questions here but nothing's helping me understand what the difference is here and what I'm missing.
<Window x:Class="TestUIWPF.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ad="http://schemas.xceed.com/wpf/xaml/avalondock"
Title="MainWindow" Height="768" Width="1024"
Loaded="MainWindow_Loaded"
xmlns:vm="clr-namespace:TestUIWPF.ViewModel"
>
<!-- lots excluded for brevity. there are no Window.Resources -->
<ad:LayoutAnchorable Title="Test" >
<Grid x:Name="gridTest">
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<StackPanel.DataContext>
<vm:EntityViewModel />
</StackPanel.DataContext>
<TextBlock Text="Label" />
<TextBlock DataContext="{Binding ActiveEntity}" Text="{Binding Path=Label}" />
</StackPanel>
<StackPanel Orientation="Horizontal" >
<TextBlock Text="Label Again" />
<TextBlock Text="{Binding Path=Label}" />
</StackPanel>
</StackPanel>
</Grid>
</ad:LayoutAnchorable>
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
this.DataContext = this;
SelectedEntityViewModel = new ViewModel.EntityViewModel();
ImportEntityXML_Click(null, null); //skips clicking the menus
}
private void ImportEntityXML_Click(object sender, RoutedEventArgs e)
{
//omitted OpenFileDialog and XmlReader stuff
xmlreader = new XmlReader(dlg.FileName);
Entities.Add(xmlreader.ReadEntityFromXML());
SimulatedEntitySelection(Entities.ElementAt(0)); //haven't built any of the UI stuff for this yet
}
private void SimulatedEntitySelection(Entity ent)
{
SelectedEntityViewModel.ActiveEntity = ent;
gridTest.DataContext = SelectedEntityViewModel.ActiveEntity;
}
private void button_Click(object sender, RoutedEventArgs e)
{
SelectedEntityViewModel.ActiveEntity.Label = "test";
}
Entity and EntityViewModel implement INotifyPropertyChanged and it works just fine with the second StackPanel. The button that calls button_Click() is just for testing the binding. EntityViewModel pretty much just wraps Entity through the ActiveEntity property and helps with reading the collections-of-collections within Entity.
EDIT3:
I've also tried a couple resources. Here's how I did the ObjectDataProvider:
<Window.Resources>
<ObjectDataProvider x:Key="testVM" ObjectType="{x:Type vm:EntityViewModel}" />
<vm:EntityViewModel x:Key="SelEntVM" />
</Window.Resources>
<!-- .... -->
<StackPanel.DataContext>
<Binding Source="{StaticResource testVM}" />
</StackPanel.DataContext>
<TextBlock Text="Label" />
<TextBlock Text="{Binding Path=ActiveEntity.Label}" />

Your first stack panel is not working, because the data context is inherited. Therefore, once you change the DataContext of the Grid to the ActiveEntity object, the binding on the text block in the first data context will set the datacontext for the TextBlock to the ActiveEntity on the current datacontext, which would already be the ActiveEntity (therefore ActiveEntity.ActiveEntity) And than try to bind to the Label property on that. E.g. ActiveEntity.ActiveEntity.Label
Before the click, you are setting the DataContext of that window to "this" which I am assuming is not the ViewModel, it is the code behind?
If you are using MVVM,
you should have something like this
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
SelectedEntityViewModel = new ViewModel.EntityViewModel();
this.DataContext = SelectedEntityViewModel;
ImportEntityXML_Click(null, null); //skips clicking the menus
}
Or some other ViewModel which provides all the necessary data.
You nomrally would have a MainWindowView and MainWindowViewModel, at least that is the convention and usually you set the datacontext of the window in the constructor once(you can do it in the Loaded handler), in most cases you shouldn't need to manually change the DataContext of any framework elements in the code behind.
EDIT: Example Code:
MainWindow.xaml
<Window x:Class="SO27760357.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="300" Width="300">
<Grid>
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<TextBlock Text="Label" />
<TextBlock Text="{Binding ActiveEntity.Label}"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Label Again" />
<TextBlock Text="{Binding ActiveEntity.Label}" />
</StackPanel>
</StackPanel>
</Grid>
</Window>
MainWindow.xaml.cs
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = new MainWindowViewModel();
}
}
MainWindowViewModel.cs (INotifyPropertChanged omitted for simplicity)
public class MainWindowViewModel
{
public EntityViewModel ActiveEntity { get; set; }
}
EntityViewModel.cs (INotifyPropertChanged omitted for simplicity)
public class EntityViewModel
{
public string Label { get; set; }
}
As you can see, I am setting the DataContext of the Window to the MainViewModel, therefore the DataContext(root of all bindings) is the MainViewModel, and each TextBlock needs to first access the ActiveEntity property first, before it can get to the Label proeprty.
THe other option is, that if everything inside the main stack panel you given us, will be bound to ActiveEntity, you can change the DataContext of that StackPanel, binding it to the ActiveEntity, and therefore all of its children datacontext will also be that object.
<StackPanel Orientation="Vertical"
**DataContext="{Binding ActiveEntity}"**>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Label" />
<TextBlock **Text="{Binding Label}"**/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Label Again" />
<TextBlock **Text="{Binding Label}"** />
</StackPanel>
</StackPanel>
EDIT 2 - Advice
You should refrain from referencing objects by name as much as possible, and have as little logic in the code behind as possible, if any. For most simple screens there is no need to have anything in code behind other than the initial Binding of the DataContext (if you don't have a window service which creates + sets the DataContext of windows)

It does work. You might be probably updating a wrong viewmodel.
Once you define the viewmodel in DataContext, youd have to access it this way:
private void button_Click(object sender, RoutedEventArgs e)
{
var myModel = (ViewModel.EntityViewModel)(yourStackPanelName.DataContext);
myModel.ActiveEntity.Label = "test";
}

Listbox bound to ObservableCollection empty

I have the following xaml:
<Window x:Class="Retail_Utilities.Dialogs.AdjustPriceDialog"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
ShowInTaskbar="False"
WindowStartupLocation="CenterOwner" Name="Adjust_Price"
Title="Adjust Price" Background="#ee0e1c64" AllowsTransparency="True" WindowStyle="None" Height="330" Width="570" KeyDown="Window_KeyDown" Loaded="Window_Loaded">
<Grid Height="300" Width="550">
<ListBox HorizontalAlignment="Right" Margin="0,110,35,60" Name="lstReasons" Width="120" VerticalAlignment="Stretch"
ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Window, AncestorLevel=1}, Path=reasons}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Path=POS_Price_Change_Reason}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
Here is the relevant c#:
namespace Retail_Utilities.Dialogs
{
public partial class AdjustPriceDialog : Window, INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public ObservableCollection<Twr_POS_Price_Change_Reason> reasons; ...
and finally, here is the code from another page that opens this window:
AdjustPriceDialog apd = new AdjustPriceDialog();
apd.Owner = (Window)this.Parent;
apd.reasons = new ObservableCollection<Twr_POS_Price_Change_Reason>();
var pcr = from pc in ctx.Twr_POS_Price_Change_Reasons where pc.Deactivated_On == null select pc;
foreach (Twr_POS_Price_Change_Reason pc in pcr)
{
apd.reasons.Add(pc);
}
apd.AdjustingDetail = (Twr_POS_Invoice_Detail)lstDetails.SelectedItem;
if (apd.ShowDialog() == true)
{
}
When the dialog box opens, my lstReasons list is empty. I don't get any errors and when I place a stop in the code, I see that the reasons collection gets populated with the items from the table.

Reasons needs to be a Property (add { get; set;} ). Also, look at Visual Studio Output - it shows Binding errors, there should be some info about failed binding to reasons.

The problem seems to be How you are creating the property.
I know you put your prperty as an observable collection but this doesn't mean it is by it self observalble!
so you need to notify the UI when this property is changed by doing something in the setter like this:
public ObservableCollection<Twr_POS_Price_Change_Reason> reasons
{
get{....}
set
{
Notify('reasons')
}
}
I don't remember the exact code because I didn't use WPF for a while but it is a method in INotifyPropertyChanged, good luck!

It seems your binding path is set to POS_Price_Change_Reason, while the name of your property is reasons. Unless you didn't include POS_Price_Change_Reason in your example code and reasons is the backing field for this property.
Also, keep in mind that you can only bind to public properties, not fields. Additionally, if you change the value of the property, you need to notify the view of this change, by invoking your PropertyChangedEventHandler event for that property:
PropertyChanged(new PropertyChangedEventArgs("YourPropertyName"));

How do you wire up views in Silverlight and MVVM using a TreeView?

I am building a Silverlight app which comprises a TreeView of menu options in a lefthand column and a ContentView in a righthand column. The idea is that the SelectedItemChanged event of the TreeView will change the view in the content area.
What is the 'purest MVVM' way of achieving this?
My idea is to have a TreeMenuView and TreeMenuViewModel for managing the menu events, but after that I'm a bit lost. I could use an EventAggregator to send a message from the TreeMenuViewModel to a `ContentViewModel' that would then set its current ContentView based on the message args- but surely that breaks MVVM, in the sense that a ViewModel shouldn't know about UI constructs like a View?
Am I missing something simple here?
How does a ViewModel layer drive the View selection?

I would create a ShellViewModel which had:
ObservableCollection<ViewModelBase> AvailablePages
int SelectedPageIndex
ViewModelBase CurrentPage, which returns AvailablePages[SelectedPageIndex]
Your ShellView can be anything you want. If you want to display your AvailablePages in a TreeView, then go ahead. Just remember to bind SelectedIndex to `SelectedPageIndex
In your case, I would create a DockPanel with a TreeView on the Left bound to AvailablePages, and a ContentControl on the right with ContentControl.Content bound to CurrentPage
Edit
Here's an example
<DockPanel>
<TreeView DockPanel.Dock="Right"
ItemsSource="{Binding AvailablePages}"
SelectedItem="{Binding SelectedPageIndex}">
...
</TreeView>
<ContentControl Content="{Binding CurrentPage}" />
</DockPanel>
Then use DataTemplates to define how the ContentControl containing CurrentPage will look
<Window.Resources>
<DataTemplate DataType="{x:Type local:HomePageViewModel}" />
<local:HomePageView />
</DataTemplate>
<DataTemplate DataType="{x:Type local:CustomerViewModel}" />
<local:CustomerView />
</DataTemplate>
</Window.Resources>

Ok I give it a shot
in TreeMenuViewModel:
public string PropSelectedItem
{
get;
set;
}
in TreeMenuView:
<TreeView Context="{Binding TreeMenuViewModel}" Content="{Binding PropSelectedItem, Mode=OneWayToSource}"/>
in ContentViewModel:
public ViewModelBase PropSelectedItem
{
get
{
switch(TreeMenuViewModelStatic.PropSelectedItem)
{
case "Booo": return typeof(View1);
case "Foo": return typeof(View2);
}
}
private set;
}
in ContentView:
<ContentControl Context="{Binding TreeMenuViewModel}" Content="{Binding PropSelectedItem, Mode=OneWay}"/>
and you need a value convertor here