WPF - Combobox does not show selecteditem - wpf

Question

Im new to WPF and VB and im having some trouble figuring out why the thing i select in a ComboBox dropdown does not show in the ComboBox after selection.
I have my ComboBox populated through bindings and DataContext. This is my Settings.xaml file
<Window.Resources>
<DataTemplate x:Key="TabList">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Header}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
...
<ComboBox x:Name="tabs"
ItemsSource="{Binding tabList}"
ItemTemplate="{StaticResource ResourceKey=TabList}"
Height="32" />
The views codebehind file (Settings.xaml.vb) then loads the ComboBoxes content in the class' constructor, and the data does show in the ComboBox
Public Class Settings
Private loader As SettingsLoader
Sub New()
InitializeComponent()
Dim sh As New SettingsHandler(True)
loader = New SettingsLoader
loader.tabList = sh.Current.Tabs
DataContext = loader
End Sub
End Class
The SettingsLoader class looks like so. TRTab is my own class that simply inherits from TabItem and only adds a few extra properties, nothing fancy
Public Class SettingsLoader
Private _tabs As List(Of TRTab)
Public Property tabList() As List(Of TRTab)
Get
Return _tabs
End Get
Set(value As List(Of TRTab))
_tabs = value
End Set
End Property
End Class
Do i need to add a property to my SettingsLoader that holds the selected item for the ComboBox to show or what am i missing ?
EDIT: Just to clarify what im trying to achieve: I have a TabControl with a number of tabs. Those tabs' Headers needs to be also shown in a ComboBox for selection

Answer 1

Because TabItem is a ContentControl the ComboBox will display its Content when the item is selected. You could confirm this yourself using the following XAML markup:
<Window.Resources>
<DataTemplate x:Key="TabList">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Header}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
<StackPanel>
<ComboBox x:Name="tabs" Height="32"
ItemTemplate="{StaticResource TabList}">
<TabItem Content="Content" Header="Header" />
</ComboBox>
</StackPanel>
When you open the dropdown, you will see "Header" but when you select the item and close the dropdown you will see "Content".
It generally doesn't make a whole much sense to set the ItemsSource property of a ComboBox to an IEnumerable of ContentControls. You could bind the ItemsSource to an IEnumerable(Of String) instead. Just add another property to your SettingsLoader class:
Public Class SettingsLoader
Private _tabs As List(Of TRTab)
Public Property tabList() As List(Of TRTab)
Get
Return _tabs
End Get
Set(value As List(Of TRTab))
_tabs = value
End Set
End Property
Public ReadOnly Property tabHeaders() As IEnumerable(Of String)
Get
If _tabs Is Nothing Then
Return Nothing
End If
Return _tabs.Select(Function(x) x.Header.ToString())
End Get
End Property
End Class
<Window.Resources>
<DataTemplate x:Key="TabList">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
<StackPanel>
<ComboBox x:Name="tabs"
ItemsSource="{Binding tabHeaders}"
ItemTemplate="{StaticResource ResourceKey=TabList}"
Height="32" />
</StackPanel>
The other option is to set the Content properties of your TRTab objects to the same values ass their Header properties.