DataBind on the DataContext of the UserControl instead of the ListBox in WPF/MVVM
===

I need to bind my ComboBox to the 'Rayons' property of the DataContext from the UserControl (instead of the ItemSources of the ListView which contains my ComboBox).

I tried to use RelativeSource but it doesn't work and I've no error message in the debug window.

A simplified code :

    <UserControl xmlns:my="clr-UI.View"
                 x:Class="UI.View.MontureView"
                 xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
                 xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WPF4"
                 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="673" d:DesignWidth="980">
            <ListView ItemsSource="{Binding Path=Monture, Mode=TwoWay}" Margin="0,39,0,95" Height="600" HorizontalAlignment="Center">
                <ListView.View>
                    <GridView>
                        <GridViewColumn >
                            <GridViewColumn.CellTemplate >
                                <DataTemplate>
                                    <ComboBox Height="25" HorizontalAlignment="Center" Width="125"
                                              Name="comboBoxRay" Margin="0,2,0,3"
                                              ItemsSource="{Binding Path=Rayons,  RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}}"
                                              SelectedValue="{Binding Path=IDRayon, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
                                              DisplayMemberPath="SRAY_LIBELLE"
                                              SelectedValuePath="SRAY_ID"  />
                                </DataTemplate>
                            </GridViewColumn.CellTemplate>
                        </GridViewColumn>
                    </GridView>
                </ListView.View>
            </ListView>
    </UserControl>

How can I handle that case ?

I found that [documentation][1] but it didn't help


  [1]: http://www.nbdtech.com/Free/WpfBinding.pdf