nportelli nportelli - 6 days ago 5
C# Question

How to Bind Blackout Days in WPF Toolkit Calendar control?

I'd like to bind a list of dates to the BlackoutDates property but it doesn't really seem to possible. Especially in a MVVM scenario. Has anyone accomplished something like this? Are there any good calendar controls that play nice with MVVM?

Answer

For your DatePicker dilemma, I found a neat hack using attached properties (modified from my use of CommandBindings):

class AttachedProperties : DependencyObject
{

    #region RegisterBlackoutDates

    // Adds a collection of command bindings to a date picker's existing BlackoutDates collection, since the collections are immutable and can't be bound to otherwise.
    //
    // Usage: <DatePicker hacks:AttachedProperties.RegisterBlackoutDates="{Binding BlackoutDates}" >

    public static DependencyProperty RegisterBlackoutDatesProperty = DependencyProperty.RegisterAttached("RegisterBlackoutDates", typeof(System.Windows.Controls.CalendarBlackoutDatesCollection), typeof(AttachedProperties), new PropertyMetadata(null, OnRegisterCommandBindingChanged));

    public static void SetRegisterBlackoutDates(UIElement element, System.Windows.Controls.CalendarBlackoutDatesCollection value)
    {
        if (element != null)
            element.SetValue(RegisterBlackoutDatesProperty, value);
    }
    public static System.Windows.Controls.CalendarBlackoutDatesCollection GetRegisterBlackoutDates(UIElement element)
    {
        return (element != null ? (System.Windows.Controls.CalendarBlackoutDatesCollection)element.GetValue(RegisterBlackoutDatesProperty) : null);
    }
    private static void OnRegisterCommandBindingChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
    {
        System.Windows.Controls.DatePicker element = sender as System.Windows.Controls.DatePicker;
        if (element != null)
        {
            System.Windows.Controls.CalendarBlackoutDatesCollection bindings = e.NewValue as System.Windows.Controls.CalendarBlackoutDatesCollection;
            if (bindings != null)
            {
                element.BlackoutDates.Clear();
                foreach (var dateRange in bindings)
                {
                    element.BlackoutDates.Add(dateRange);
                }
            }
        }
    }

    #endregion
}

I'm sure I'm too late to help you out, but hopefully someone else will find it useful.

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