WPF在菜单显示之前更新上下文菜单项

Question

I'm using WPF with Caliburn and the MVVM pattern and I'm trying to set up a dynamic context menu.

Currently we have a context menu with it's Items bound to a BindableCollection on the ViewModel.

<UserControl.ContextMenu>
         <ContextMenu ItemsSource="{Binding AvailableActions}"
                      actions:Action.TargetWithoutContext="{Binding}"
                      ItemContainerStyleSelector="{StaticResource NamedActionStyleSelector}"/>
</UserControl.ContextMenu>

public BindableCollection<NamedAction> AvailableActions { get; set; }

This BindableCollection is updated in certain circumstances during the running of the program by the method (Again on the view model):

private void UpdateAvailableActions()

The current system works well for most situations but there are a few edge cases that suggest that we would be better served to dynamically generate the list after a right click event.

So my question is, can anyone help me with the best way to call the update method (or write an alternative method which would be called) when the user has right clicked. Any help with how to do this would be greatly appreciated.

Thanks

Answer 1

Personally, I'm a big fan of using OnPropertyChanged() from IPropertyNotifyChanged . This way you can create a command that gets executed on right clicking that calls OnPropertyChanged() . You will have to do a little research yourself about how you want to implement events as commands since you're using MVVM, a starting point can be found here or here . Alternatively, you can get creative with the CommandParameter binding and use that in your command.

Hope that helps!