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WPF / MVVM - Title Binding

I'm using MVVM pattern in WPF. My small project contains 1x Window and 3x UserControls. Each UserControl represents tab, please see the picture below.
Solution structure
What I'm trying to do is to bind the Window Title to the variable in each tab model. I tried to use Interaction.Triggers and event name "Loaded". The command "ChangeTitle" works fine when I switch between different views but when I select tab with the same view as previously selected tab then title doesn't change until I switch to another tab with different view. I tried other events but couldn't find any for this purpose. I would like to trigger the above command after tab selection changed. Please advise. Thank you.
MainWindow.xaml
<Window x:Class="LSS_doc.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:intr="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:models="clr-namespace:LSS_doc.Models"
xmlns:Views="clr-namespace:LSS_doc.Views"
mc:Ignorable="d"
Height="350" Width="525"
MinHeight="350"
MinWidth="525">
<Grid>
<intr:Interaction.Triggers>
<intr:EventTrigger EventName="Loaded">
<intr:InvokeCommandAction Command="{Binding CreateMainTab}"/>
</intr:EventTrigger>
</intr:Interaction.Triggers>
<DockPanel>
<TabControl Name="tabControl" ItemsSource="{Binding Tabs}" SelectedIndex="{Binding TabIndex}">
<TabControl.Resources>
<DataTemplate DataType="{x:Type models:MainTabModel}">
<Views:MainTabView/>
</DataTemplate>
<DataTemplate DataType="{x:Type models:ResultTabModel}">
<Views:ResultTabView/>
</DataTemplate>
<DataTemplate DataType="{x:Type models:DisplayTabView}">
<Views:DisplayTabView/>
</DataTemplate>
</TabControl.Resources>
<TabControl.ItemTemplate>
<DataTemplate DataType="{x:Type models:ITabModel}">
<TextBlock>
<Run Text="{Binding Name}"/>
<Hyperlink Command="{Binding CloseCommand}" ><Run Text="{Binding CloseButton}"/></Hyperlink>
</TextBlock>
</DataTemplate>
</TabControl.ItemTemplate>
</TabControl>
</DockPanel>
</Grid>
MainTabView.xaml
<UserControl x:Class="LSS_doc.Views.MainTabView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:intr="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<intr:Interaction.Triggers>
<intr:EventTrigger EventName="Loaded">
<intr:InvokeCommandAction CommandParameter="{Binding Name}" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.ChangeTitle}"/>
</intr:EventTrigger>
</intr:Interaction.Triggers>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="100"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="50"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<TextBox Name="searchBox" Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.Keywords}" Margin="10,10,10,10" Height="30"/>
<Button Name="searchButton" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.Search}" Grid.Column="1" Margin="0,0,10,0" Height="30"/>
<TreeView Grid.Row="1" Grid.ColumnSpan="2" Margin="10,0,10,10" BorderThickness="0">
<TreeViewItem Header="{Binding Name}" IsExpanded="True">
<TreeViewItem Header="Level 2.1" />
<TreeViewItem Header="Level 2.2" IsExpanded="True">
<TreeViewItem Header="Level 3.1" />
<TreeViewItem Header="Level 3.2" />
</TreeViewItem>
<TreeViewItem Header="Level 2.3" />
</TreeViewItem>
</TreeView>
</Grid>
ResultTabView.xaml
<UserControl x:Class="LSS_doc.Views.ResultTabView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:intr="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<intr:Interaction.Triggers>
<intr:EventTrigger EventName="Loaded">
<intr:InvokeCommandAction CommandParameter="{Binding Name}" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.ChangeTitle}"/>
</intr:EventTrigger>
</intr:Interaction.Triggers>
<Grid>
<ListBox x:Name="FileList" ItemsSource="{Binding Result}">
<ListBox.ItemTemplate>
<DataTemplate DataType="string">
<TextBlock>
<Hyperlink CommandParameter="{Binding}" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.DisplayFile}">
<TextBlock Text="{Binding}"/>
</Hyperlink>
</TextBlock>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
DisplayTabView.xaml
<UserControl x:Class="LSS_doc.Views.DisplayTabView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:intr="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:LSS_doc.Helpers"
xmlns:ns="clr-namespace:LSS_doc.Helpers"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<intr:Interaction.Triggers>
<intr:EventTrigger EventName="Loaded">
<intr:InvokeCommandAction CommandParameter="{Binding Name}" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.ChangeTitle}"/>
</intr:EventTrigger>
</intr:Interaction.Triggers>
<Grid >
<WebBrowser local:WebBrowserExtensions.BindableSource="{Binding FileUrl}" local:WebBrowserExtensions.BindableLoaded="{Binding AcceptedKeywords}"/>
</Grid>

You can bind Window Title directly to model using ElementName:
<Window Title="{Binding ElementName=tab,Path=SelectedItem.WindowTitleForThisTab}">

Binding contextmenu command in a tree view with hierarchical data template

I have a treeview with hierarchical data template and I am trying to set DataContext for ContextMenu, so I could bind commands to it. I have done research and know that ContextMenu doesn't inherit DataContext of its parent. I tried to follow these posts: How to set the RelativeSource in a DataTemplate that is nested in a HierarchicalDataTemplate?
How to bind to the DataContext of a HierarchicalDataTemplate from its ItemTemplate XAML? but still can't get it to work. Any help would be appreciated. Here is my sample code:
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type viewModels:SiteViewModel}" ItemsSource="{Binding Children}">
<StackPanel Orientation="Horizontal">
<StackPanel.Resources>
</StackPanel.Resources>
<Image Width="16" Height="16" Margin="3,0" />
<TextBlock Text="{Binding SiteName}" />
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type viewModels:LevelViewModel}" ItemsSource="{Binding Children}" >
<StackPanel Orientation="Horizontal" >
<Image Width="16" Height="16" Margin="3,0" />
<TextBlock Text="{Binding LevelName}" >
<TextBlock.ContextMenu >
<ContextMenu>
<MenuItem Header="Test" Command="{Binding ?????????" CommandParameter="{Binding}"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>

One way to solve it:
In my case I had something like that:
<DataTemplate DataType="...">
<TreeView>
<TreeViewItem Tag="{Binding ElementName=LocalControl, Path=DataContext}"
Header="{Binding ...}"
ContextMenu="{StaticResource ...}">
...
</TreeViewItem>
</TreeView>
</DataTemplate>
You need to bind Tag attribute of parent TreeViewItem to its DataContext, then somewhere in your hierarchical templates for context menu you should bind its DataContext to Tag of parent control:
<ContextMenu x:Key="CyclogramFolderContextMenu"
DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<TextBlock Text="Do something" >
<TextBlock.InputBindings>
<MouseBinding Command="{Binding Path=(viewModels:someViewModel.SomeCommand)}" MouseAction="LeftClick" />
</TextBlock.InputBindings>
</TextBlock>
</ContextMenu>

Bind to command from within a treeview

I'm building a treeview with HierarchicalDataTemplates and would like to bind the nodes to a command from my MainViewModel. I guess there is some conflict with the scopes, since the binding works if I e.g. use a button and define it outside of the treeview. If I define it inside, however, it does not work.
I've searched through Stackoverflow and found several solutions but none that worked for me. Jehof e.g. suggested here to use
<Button Command="{Binding DataContext.Command,
RelativeSource={RelativeSource AncestorLevel=2, AncestorType=TreeViewItem}}"
CommandParameter="{Binding}" />
but that did not work. Thank you for any suggestions!
<TreeView ItemsSource="{Binding _questions}" Grid.Row="0" Margin="10" BorderThickness="1">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type local:Question}" ItemsSource="{Binding Converter={StaticResource QuestionConverter}}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Name}" />
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type local:MainOption}" ItemsSource="{Binding MainOptions}">
<StackPanel Orientation="Horizontal">
<CheckBox Content="{Binding Path=Name}" />
/////////////////////////////////////
<Button Command="{Binding ThisIsMyCommand}" Content="Click Me"/>
/////////////////////////////////////
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.Resources>

Is your TreeView-Control inside a Window or UserControl?
If you are inside a Window:
<Button Command="{Binding DataContext.Command, RelativeSource={RelativeSource FindAncestor, AncestorType=Window}}" CommandParameter="{Binding}" />
and for UserControl
<Button Command="{Binding DataContext.Command, RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl}}" CommandParameter="{Binding}" />

Get ContextMenu Datacontext of Parent

I have a ContextMenu binded to a CommandBinding:
<MetroTreeView:MetroTreeView x:Name="tvTagList" Grid.Row="1" Margin="15, 0, 15, 0" SelectedItemChanged="tvTagList_SelectedTagChanged" ItemsSource="{Binding}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Background="{x:Null}" BorderBrush="{DynamicResource ExtryzeAccentBrushSecondary}" BorderThickness="2" Foreground="White"
VirtualizingStackPanel.IsVirtualizing="True" VirtualizingStackPanel.VirtualizationMode="Standard">
<MetroTreeView:MetroTreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type DataBind:TagClass}" ItemsSource="{Binding Children}" >
<StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch">
<TextBlock>
<Run Text="{Binding TagClassMagic}" />
<Run Foreground="{StaticResource TextBrushSecondary}" Text=" - " />
<Run Foreground="{StaticResource TextBrushSecondary}" Text="{Binding Path=Description, Converter={StaticResource IValueTagDescriptionCleanup}}" />
</TextBlock>
<StackPanel.ContextMenu>
<ContextMenu>
<MenuItem Header="Dump Tag List..." Click="DumpClassTagList" />
</ContextMenu>
</StackPanel.ContextMenu>
</StackPanel>
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type DataBind:TagEntry}">
<StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch">
<StackPanel.ContextMenu>
<ContextMenu>
<ContextMenu.CommandBindings>
<CommandBinding Command="{x:Static DataBind:HaloMap.CommandTagBookmarking }"
CanExecute="CommandTagBookmarking_CanExecute"
Executed="CommandTagBookmarking_Executed"
/>
</ContextMenu.CommandBindings>
<MenuItem Header="Bookmark Tag" Foreground="White" Command="{x:Static DataBind:HaloMap.CommandTagBookmarking}" CommandParameter="{Binding}" />
</ContextMenu>
</StackPanel.ContextMenu>
<TextBlock Text="{Binding TagFileName}" />
</StackPanel>
</DataTemplate>
</MetroTreeView:MetroTreeView.Resources>
<MetroTreeView:MetroTreeView.ItemContainerStyle>
<Style TargetType="{x:Type MetroTreeView:MetroTreeViewItem}" BasedOn="{StaticResource {x:Type MetroTreeView:MetroTreeViewItem}}">
<EventSetter Event="MouseDoubleClick" Handler="tvTagList_ItemDoubleClick" />
</Style>
</MetroTreeView:MetroTreeView.ItemContainerStyle>
But when I run the CanExecute command, every attempt to access the DataContext is always met with a null:
private void CommandTagBookmarking_CanExecute(object sender, CanExecuteRoutedEventArgs e)
{
var a = e.Source;
var b = ((MenuItem)a).DataContext;
var c = ((ContextMenu) ((MenuItem) e.Source).Parent).DataContext;
}

Try this:
<ContextMenu DataContext="{Binding PlacementTarget, RelativeSource={RelativeSource Self}}">

Since ContextMenu don't lie in the VisualTree of the object where it's placed. You have to inherit the DataContext of object using PlacementTarget -
<ContextMenu DataContext="{Binding PlacementTarget.DataContext,
RelativeSource={RelativeSource Self}}">

How to display context menu for treeview item in a hierarchial data template in wpf

How to display context menu for tree view item in wpf using the hierarchical data template? How to display context menu only for CountryTemplate:
<HierarchicalDataTemplate x:Key="DispTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Label}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}" Tag="{Binding Path=Tag}">
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="BuildingTemplate" ItemsSource="{Binding Path=Building}" ItemTemplate="{StaticResource BuildingTemplate}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Label}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}"/>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="CityTemplate" ItemsSource="{Binding Path=City}" ItemTemplate="{StaticResource CityTemplate}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Label}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}"/>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="CountryTemplate" ItemsSource="{Binding Path=Country}" ItemTemplate="{StaticResource CountryTemplate}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=RootName}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}"/>
</StackPanel>
</HierarchicalDataTemplate>

You also can add the ContextMenu to any visual child in the data template, for instance:
<HierarchicalDataTemplate x:Key="CountryTemplate" ItemsSource="{Binding Path=Country}" ItemTemplate="{StaticResource CountryTemplate}">
<StackPanel Orientation="Horizontal">
<StackPanel.ContextMenu>
<ContextMenu>
<MenuItem Header="Header" Command="{Binding Command}"/> <!--This command should be in the data context (each country item)-->
</ContextMenu>
</StackPanel.ContextMenu>
<TextBlock Text="{Binding Path=RootName}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}"/>
</StackPanel>
</HierarchicalDataTemplate>

One of the reasons why context menus do not work as cleanly as they could is because by default, they are in a different visual tree to everything else, so the DataContext cannot be found.
The key insight is to create a <Style> that defines a context menu,
then attach that style to a target element, which hooks up the context
menu. This shifts the context menu into a visual tree that is lined up with the default DataContext you want.
First, create the style:
<UserControl.Resources>
<ResourceDictionary>
<!-- For the context menu to work, we must shift it into a style, which means that the context menu is now in a
visual tree that is more closely related to the current data context. All we have to do then is set the style,
which hooks up the context menu. -->
<Style x:Key="ContextMenuStyle" TargetType="{x:Type StackPanel}">
<Setter Property="ContextMenu" Value="{DynamicResource TreeViewContextMenu}"/>
</Style>
<ContextMenu x:Key="TreeViewContextMenu">
<MenuItem Header="Test" Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, Path=DataContext.CmdDisplayDetailsGraph}"/>
</ContextMenu>
Then, hook the context menu up anywhere you want, without running into issues caused by different visual trees.
Example 1:
<HierarchicalDataTemplate DataType="{x:Type snapshot:Details}" ItemsSource="{Binding DetailsList}">
<StackPanel Orientation="Vertical" Style="{StaticResource ContextMenuStyle}">
<ContentPresenter Content="{Binding}" ContentTemplate="{Binding View.DefaultDataRowTemplate}" />
</StackPanel>
Example 2:
<DataTemplate DataType="{x:Type snapshot:InstrumentDetails}">
<StackPanel Orientation="Vertical" Style="{StaticResource ContextMenuStyle}">
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Center">

<HierarchicalDataTemplate x:Key="CountryTemplate" ItemsSource="{Binding Path=Country}" ItemContainerStyle="{StaticResource CountryTemplateItemContainerStyle}" ItemTemplate="{StaticResource CountryTemplate}">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=RootName}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}" />
</StackPanel>
</HierarchicalDataTemplate>
<Style x:Key="CountryTemplateItemContainerStyle" TargetType="{x:Type TreeViewItem}">
<Setter Property="ContextMenu" Value="{DynamicResource TreeViewContextMenu}"/>
</Style>
<ContextMenu x:Key="TreeViewContextMenu">
<MenuItem .../>
</ContextMenu>
As you can see, you can add your contextmenu in the Itemcontainerstyle of the HierarchicalDataTemplate

Basically I came up with this
<HierarchicalDataTemplate x:Key="ChildTemplate">
<StackPanel Orientation="Horizontal">
<StackPanel.ContextMenu>
<ContextMenu>
<MenuItem Header="Copy" CommandParameter="{Binding CopyTag}">
</MenuItem>
<MenuItem Header="Paste" CommandParameter="{Binding PasteTag}">
</MenuItem>
<ContextMenu.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command" Value="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, Path=DataContext.CopyPaste}"/>
</Style>
</ContextMenu.ItemContainerStyle>
</ContextMenu>
</StackPanel.ContextMenu>
<Image Source="/Images/Child.png" Stretch="None" VerticalAlignment="Center" HorizontalAlignment="Center" Style="{StaticResource TreeIconStyle}"/>
<TextBlock Text="{Binding Path=Label}" Style="{StaticResource TreeTextStyle}" ToolTip="{Binding Path=Description}" Tag="{Binding Path=Tag}">
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
And have separate parameters for copy and paste to differentiate copy and paste in a single command.