Binding one dependency property to another - wpf

Question

I have a custom Tab Control that I have created, but I am having an issue. I have an Editable TextBox as part of the custom TabControl View.
<Controls:EditableTextControl x:Name="PageTypeName"
Style="{StaticResource ResourceKey={x:Type Controls:EditableTextControl}}" Grid.Row="0" TabIndex="0"
Uid="0"
AutomationProperties.AutomationId="PageTypeNameTextBox"
AutomationProperties.Name="PageTypeName"
Visibility="{Binding ElementName=PageTabControl,Path=ShowPageType}">
<Controls:EditableTextControl.ContextMenu>
<ContextMenu x:Name="TabContextMenu">
<MenuItem Header="Rename Page Type" Command="{Binding Path=PlacementTarget.EnterEditMode, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
AutomationProperties.AutomationId="RenamePageTypeMenuItem"
AutomationProperties.Name="RenamePageType"/>
<MenuItem Header="Delete Page Type" Command="{Binding Path=PageTypeDeletedCommand}"
AutomationProperties.AutomationId="DeletePageTypeMenuItem"
AutomationProperties.Name="DeletePageType"/>
</ContextMenu>
</Controls:EditableTextControl.ContextMenu>
<Controls:EditableTextControl.Content>
<!--<Binding Path="CurrentPageTypeViewModel.Name" Mode="TwoWay"/>-->
<Binding ElementName="PageTabControl" Path="CurrentPageTypeName" Mode ="TwoWay"/>
</Controls:EditableTextControl.Content>
</Controls:EditableTextControl>
In the Content section I am binding to a Dependency Prop called CurrentPageTypeName. This Depedency prop is part of this custom Tab Control.
public static DependencyProperty CurrentPageTypeNameProperty = DependencyProperty.Register("CurrentPageTypeName", typeof(object), typeof(TabControlView));
public object CurrentPageTypeName
{
get { return GetValue(CurrentPageTypeNameProperty) as object; }
set { SetValue(CurrentPageTypeNameProperty, value); }
}
In another view, where I am using the custom TabControl I then bind my property, with the actual name value, to CurrentPageTypeName property as seen below:
<Views:TabControlView Grid.Row="0" Name="RunPageTabControl"
TabItemsSource="{Binding RunPageTypeViewModels}"
SelectedTab="{Binding Converter={StaticResource debugConverter}}"
CurrentPageTypeName="{Binding Path=RunPageName, Mode=TwoWay}"
TabContentTemplateSelector="{StaticResource tabItemTemplateSelector}"
SelectedIndex="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, Path=DataContext.SelectedTabIndex}"
ShowPageType="Hidden" >
<!--<Views:TabControlView.TabContentTemplate>
<DataTemplate DataType="{x:Type ViewModels:RunPageTypeViewModel}">
<RunViews:RunPageTypeView/>
</DataTemplate>
</Views:TabControlView.TabContentTemplate>-->
</Views:TabControlView>
My problem is that nothing seems to be happening. It is grabbing its Content from the Itemsource, and not from my chained Dependency props. Is what I am trying even possible? If so, what have I done wrong.
Thanks for looking.

Answer 1

Unless I'm missing something this is definitely possible. Here is a simplified working example.
User control with a dependency property named TestValue, containing a TextBox bound to this property:
<UserControl x:Class="TestApp.TestControl" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"
x:Name="TestControlName">
<Grid>
<TextBox Text="{Binding ElementName=TestControlName, Path=TestValue, Mode=TwoWay}"/>
</Grid>
</UserControl>
A different view using this user control, binding the above mentioned dependency property to something:
<Window x:Class="TestApp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:TestApp="clr-namespace:TestApp" Title="MainWindow"
Height="350" Width="525">
<StackPanel>
<TestApp:TestControl TestValue="{Binding ElementName=SourceTextBox, Path=Text, Mode=TwoWay}" />
<TextBox Name="SourceTextBox" />
</StackPanel>
</Window>
It sounds that the issue is somewhere in the part of the code you have not posted (e.g. wrong name used in Content binding).

Answer 2

I think you already solved this yourself for the "SelectedIndex" property. Just do the same thing for the "CurrentPageType" property i.e. use RelativeSource