Selected ComboBoxItem image is not changing

Question

I have this ComboBox that is bound to an ObservableCollection:

<ComboBox x:Name="comboMeetingWeek" ItemsSource="{Binding Meetings}"
    SelectedItem="{Binding Meeting, UpdateSourceTrigger=PropertyChanged}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Horizontal">
                <Image Source="Images/Bell.png" Margin="0,0,5,0"
                       Visibility="{Binding DisplayBellImage, Converter={StaticResource BoolToHiddenConverter}}" Stretch="None"/>
                <TextBlock Text="{Binding DateMeetingAsText}" />
            </StackPanel>
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

And I have this ContextMenu that I am working on implementing (a work in progress):

<Image Grid.Column="1" HorizontalAlignment="Right" Source="Images\event_time.png" Margin="2">
    <Image.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Set Special Event" Command="{Binding SetSpecialEventCommand, Mode=OneWay}"/>
            <MenuItem Header="Edit Special Event" Command="{Binding EditSpecialEventCommand, Mode=OneWay}"/>
            <MenuItem Header="Remove Special Event">
                <MenuItem.Style>
                    <Style TargetType="MenuItem">
                        <Setter Property="IsEnabled" Value="False"/>
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding Meeting.IsSpecialEvent}" Value="True">
                                <Setter Property="IsEnabled" Value="True"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </MenuItem.Style>
            </MenuItem>
        </ContextMenu>
    </Image.ContextMenu>
</Image>

Ignoring Remove Special Event for now.

Here are the two associated Commands:

_SetSpecialEventCommand = new DelegateCommand<string>(
    (s) =>
    {
        SpecialEventWindow windowEvent = new SpecialEventWindow();
        windowEvent.DataContext = this;
        windowEvent.ShowDialog();
        if (windowEvent.DialogResult.HasValue && windowEvent.DialogResult.Value)
            _Meeting.IsSpecialEvent = true;
    },
    (s) => !_Meeting.IsSpecialEvent);

_EditSpecialEventCommand = new DelegateCommand<string>(
    (s) =>
    {
        SpecialEventWindow windowEvent = new SpecialEventWindow();
        windowEvent.DataContext = this;
        windowEvent.ShowDialog();
        if (windowEvent.DialogResult.HasValue && windowEvent.DialogResult.Value)
            _Meeting.IsSpecialEvent = true;
        else
            _Meeting.IsSpecialEvent = false;
    },
    (s) => _Meeting.IsSpecialEvent);

And, so that the ContextMenu will correctly set the menu states the next time around it does:

public Data.MeetingInfo.Meeting Meeting
{
    get { return _Meeting; }
    set
    {
        // Has the existing meeting object changed at all?
        if(_Meeting != null && _Meeting.IsDirty)
        {
            // Yes, so save it
            _Model.Serialize();
            _Meeting.MarkClean();
        }

        // Now we can update to new value
        if (value != null)
        {
            _Meeting = value;
            OnPropertyChanged("Meeting");
            _SetSpecialEventCommand.RaiseCanExecuteChanged();
            _EditSpecialEventCommand.RaiseCanExecuteChanged();
        }
    }
}
private Data.MeetingInfo.Meeting _Meeting;

So my context menu now always matches the state of the current combo menu item.

But when I set a combo item as an event when it was not one before, the combo item does not update and add the image. I decided to set the ItemSource to also have an UpdateTriggerSource=PropertyChanged.

Then, I adjusted my listening event handler:

private void Meeting_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
    OnPropertyChanged(e.PropertyName);

    if (e.PropertyName == "IsSpecialEvent" || e.PropertyName == "IsCircuitVisit")
        OnPropertyChanged("Meetings");
}

But that is not working right. The list shows it now with an icon but not the current item itself.

What step am I missing?

In order to see it I must pick another menu item and then come back to it.

Thank you.

Update

I changed my two Model properties:

[XmlIgnore]
public bool IsSpecialEvent
{
    get { return _SpecialEvent.Event; }
    set
    {
        _SpecialEvent.Event = value;
        MarkDirty();
        OnPropertyChanged("IsSpecialEvent");
        OnPropertyChanged("DisplayBellImage");
    }
}

[XmlIgnore]
public bool IsCircuitVisit
{
    get { return _SpecialEvent.CircuitVisit; }
    set
    {
        _SpecialEvent.CircuitVisit = value;
        MarkDirty();
        OnPropertyChanged("IsCircuitVisit");
        OnPropertyChanged("DisplayBellImage");
    }
}

They now also fire the DisplayBellImage and all seems good. But I did need to update the ItemSource the way that I did, right?

Answer 1

The visibility of the bell image seems to be driven by the value of a property called DisplayBellImage. I don't see you ever changing the value of that property, or raising PropertyChanged for it. You should be calling OnPropertyChanged("DisplayBellImage"); every time the value of DisplayBellImage changes.