Question

I have a context menu that is tied to a button in a datagrid. I want the context menu items to change based on a list of strings that I have in my view model. When I click the button, nothing shows up.

Here is the xaml I am using, which is in a datagrid:

<Button Grid.Column="1" Content="..."  Click="Button_Click">
        <Button.ContextMenu>
       <ContextMenu ItemsSource="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type UserControl}},Path=DataContext.SelectableDescriptions}">    
         <TextBlock Text="{Binding}"/>
       </ContextMenu>
       </Button.ContextMenu>        
</Button>

Here’s the whole DataGrid xaml:

<DataGrid Grid.Row="1" Grid.ColumnSpan="4" CanUserAddRows="True" AutoGenerateColumns="False" CanUserDeleteRows="True"  ItemsSource="{Binding JobPricings, Mode=TwoWay}" SelectedItem="{Binding SelectedJobPricing, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
    <DataGrid.Columns>
        <DataGridTemplateColumn  Header="Description" Width="25*"   >
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="75*"/>
                            <ColumnDefinition Width="25*"/>
                        </Grid.ColumnDefinitions>
                        <TextBox Grid.Column="0" Text="{Binding Description,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
                        <Button Grid.Column="1" Content="..."  Click="Button_Click">
                            <Button.ContextMenu>
                                <ContextMenu ItemsSource="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type UserControl}},Path=DataContext.SelectableDescriptions}">
                                    <TextBlock Text="{Binding}"/>
                                </ContextMenu>
                            </Button.ContextMenu>
                        </Button>
                    </Grid>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
         </DataGridTemplateColumn>
        <DataGridTextColumn Header="Unit Price" Binding="{Binding UnitPrice, Mode=TwoWay}" Width="25*"/>
        <DataGridTextColumn Header="Unit" Binding="{Binding Unit, Mode=TwoWay}" Width="25*"/>
        <DataGridTemplateColumn  Header="Currency   " Width="25*" >
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <Grid>
                        <ComboBox  SelectedValue="{Binding CurrencyID, Mode=TwoWay}" SelectedValuePath="ID" DisplayMemberPath="Description" ItemsSource="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type UserControl}},Path=DataContext.Currencies}"  ></ComboBox>
                    </Grid>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Here is the property that I am binding the context menu to through my view model:

public ObservableCollection<string> SelectableDescriptions
{
    get
    {
        _selectableDescriptions.Add("One");
        _selectableDescriptions.Add("Two");
        return _selectableDescriptions;
    }
    set
    {
        _selectableDescriptions = value;
    }
}

Any ideas of why my list won’t show up in the context menu?

Answer 1

I ended up setting the ItemsSource for the ContextMenu in the code behind (even though I really didn’t want to use that approach:), which worked

Here’s the xaml

<Button Grid.Column="1" Content="..."  Name="ellipseButton" Click="ellipseButton_Click">
    <Button.ContextMenu>
       <ContextMenu >
          <ContextMenu.ItemTemplate>
              <DataTemplate>
                   <TextBlock Text="{Binding}" />
              </DataTemplate>
          </ContextMenu.ItemTemplate>
        </ContextMenu>
     </Button.ContextMenu>
</Button>

Here’s the code behind:

private void ellipseButton_Click(object sender, RoutedEventArgs e)
{
    var button = sender as Button;
    button.ContextMenu.ItemsSource = JobPricingViewModel.SelectableDescriptions;
    if (button != null) button.ContextMenu.IsEnabled = true;
    var placementTarget = sender as Button;
    if (placementTarget != null) placementTarget.ContextMenu.PlacementTarget = placementTarget;
    var button1 = sender as Button;
    if (button1 != null)
        button1.ContextMenu.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;
    var button2 = sender as Button;
    if (button2 != null) button2.ContextMenu.IsOpen = true;
}