Can Breadcrumb items be bound to commands?

[Joshua]

Hi, I have not been able to find documentation yet on how to handle events generated by the RadBreadcrumb control, can you point me at the docs?  I would really like to bind inidividual 'crumbs' to an ICommand using MVVM. (the same way I would bind a button's Command property to an ICommand)  If that's not possible, is there anything else I can do to bind to this control, or do I have to use the events?

[Dilyan Traykov]

Hello Joshua,

When you need to bind events to command in your viewmodel following the MVVM pattern, you can use the EventToCommandBehavior helper class. Here's how you can set it up in this case:

<telerik:RadBreadcrumb>
    <telerik:EventToCommandBehavior.EventBindings>
        <telerik:EventBinding EventName="MouseLeftButtonDown" Command="{Binding ClickCommand}" PassEventArgsToCommand="True" RaiseOnHandledEvents="True" />
    </telerik:EventToCommandBehavior.EventBindings>
    <!-- ... -->
</telerik:RadBreadcrumb>

Note that the MouseLeftButtonDown event is handled internally, you need to set the RaiseOnHandledEvents property of the EventBinding to True.

In addition, you will probably require the event arguments in your command's logic. This is where the PassEventArgsToCommand property comes in handy.

Here's how you can get the item that has been clicked:

public class MainWindowViewModel : ViewModelBase
{
    public ICommand ClickCommand { get; set; }

    public MainWindowViewModel()
    {
        this.ClickCommand = new DelegateCommand(OnClick);
    }

    private void OnClick(object obj)
    {
        var args = obj as MouseButtonEventArgs;
        var source = args.OriginalSource as FrameworkElement;
        var item = source.ParentOfType<RadBreadcrumbBarItem>();
        if (item != null)
        {
            Debug.WriteLine(item.Header);
        }
    }
}

For your convenience, I'm also attaching a sample project with the implementation.

I hope you find all of this helpful. Should any further questions or concerns arise, please let me know.

Regards,
Dilyan Traykov
Progress Telerik