将BooleanToVisibilityConverter绑定到TreeView HierarchicalDataTemplate中的控件

Question

I have a TreeView object bound to a DataSet. Inside of the TreeView.ItemTemplate, I am using a HierarchicalDataTemplate containing the controls that I am rendering.

Does anyone know how to change the Visibility property of a control inside of a HierarchicalDataTemplate? I have tried using the BooleanToVisibilityConverter from the .NET framework, but cannot get the binding to work properly.

The boolean variable in my ViewModel named " moveButtonVisibility " is bound to the Visibility property of the button in my XAML. The BooleanToVisibilityConverter then attempts to convert the corresponding boolean value (true/false) to a Visibility value (visible/hidden). " moveButtonVisibility " is not part of the TreeView's ItemSource.

A stripped down version of my code is shown below. I have removed all of the code in my XAML except for the Button control "MoveHereButton" that I want to change the visibility property on:

VIEWMODEL (C#):

private bool _moveButtonVisibility;
public bool moveButtonVisibility
{
    get { return _moveButtonVisibility; }
    set
    {
        _moveButtonVisibility = value;
        RaiseChange("moveButtonVisibility");
    }
}

VIEW (XAML):

<Page>
     <Page.Resources>
         <BooleanToVisibilityConverter x:Key="visibilityConverter"/>
     </Page.Resources>
     <Grid HorizontalAlignment="Center" VerticalAlignment="Top">
        <TreeView HorizontalAlignment="Center" x:Name="treeView1" VerticalAlignment="Top" ItemsSource="{Binding Path=rsParentChild}"  Background="Transparent" BorderThickness="0" BorderBrush="Transparent" >
            <TreeView.ItemContainerStyle>
               <Style>
                  <Setter Property="TreeViewItem.IsExpanded" Value="True"/>
               </Style>
            </TreeView.ItemContainerStyle>
            <TreeView.ItemTemplate>
                 <HierarchicalDataTemplate ItemsSource="{Binding Path=rsParentChild, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
                        <Grid Focusable="False" Margin="5,10,5,10">
                           <Grid.ColumnDefinitions>
                               <ColumnDefinition Width="1*"/>
                            </Grid.ColumnDefinitions>
                            <Grid.RowDefinitions>
                                <RowDefinition/>
                             </Grid.RowDefinitions>
                             <Button Name="MoveHereButton" Content="Move Here" Visibility="{Binding DataContext.moveButtonVisibility, Converter={StaticResource visibilityConverter}}" Click="MoveHereButton_Click" />
                        </Grid>
                 </HierarchicalDataTemplate>
             </TreeView.ItemTemplate>
        </TreeView>
    </Grid>
</Page>

Answer 1

The following worked:

<Button Name="MoveHereButton"  
        Content="Move Here" 
        Visibility="{Binding DataContext.moveButtonVisibility, 
                      RelativeSource={RelativeSource AncestorType={x:Type Page}},
                      Converter={StaticResource visibilityConverter}}" 
        Click="MoveHereButton_Click" />

The key was to add:

RelativeSource={RelativeSource AncestorType={x:Type Page}}

inside of the Visibility binding to force the control to use the DataContext of the Page .