如何在附加行为中将MouseDoubleClick连接到ViewModel？

Question

我正在尝试在MVVM模式中实现附加行为功能。我有一个Calendar控件，想要处理MouseDoubleClick事件。我是使用System.Windows.Interactivity和Interaction.Triggers做的。但是，我也在BlackoutDates中使用Calendar并双击停电日期会导致最后一个有效的选定日期传递到MouseDoubleClick方法，而不是点击的日期。

所以我现在定位CalendarDayButton，它会让我点击日期，但CDB没有Commands，所以我需要使用附加行为。但我仍然不了解如何将MouseDoubleClick处理程序信息导入ViewModel。我目前的代码：

查看

<Calendar HorizontalAlignment="Left" VerticalAlignment="Top" Margin="20,48,0,0" 
          SelectedDate="{Binding ReportDate, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
          DisplayDateStart="{Binding ReportDateStart, Mode=OneTime}" 
          DisplayDateEnd="{Binding ReportDateEnd, Mode=OneTime}" 
          local:AttachedProperties.RegisterBlackoutDates="{Binding NoProdDates, Mode=OneWay}">
    <Calendar.CalendarDayButtonStyle>
        <Style TargetType="CalendarDayButton">
            <Setter Property="local:AttachedBehaviors.IsValidDateSelected" 
                    Value="{Binding ValidDateSelected, Mode=TwoWay}"/>
        </Style>
    </Calendar.CalendarDayButtonStyle>
</Calendar>

的视图模型

...
private bool validDateSelected;

public bool ValidDateSelected
{
    get { return validDateSelected; }

    set
    {
        if (validDateSelected != value)
        {
            validDateSelected = value;
            RaisePropertyChanged("ValidDateSelected");
        }
    }
}
...

附加行为类

using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Input;


namespace MDOD
{
    public class AttachedBehaviors : DependencyObject
    {
        public static readonly DependencyProperty IsValidDateSelectedProperty =
            DependencyProperty.RegisterAttached("IsValidDateSelected", typeof(bool), typeof(AttachedBehaviors), 
            new UIPropertyMetadata(false, OnIsValidDateSelectedChanged));


        public static bool GetIsValidDateSelected(DependencyObject obj)
        {
            return (bool)obj.GetValue(IsValidDateSelectedProperty);
        }


        public static void SetIsValidDateSelected(DependencyObject obj, bool value)
        {
            obj.SetValue(IsValidDateSelectedProperty, value);
        }


        private static void OnIsValidDateSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CalendarDayButton cdb = d as CalendarDayButton;

            if (cdb != null)
            {
                if ((bool)e.NewValue)
                {
                    cdb.MouseDoubleClick += cdb_MouseDoubleClick;
                }
                else
                {
                    cdb.MouseDoubleClick -= cdb_MouseDoubleClick;
                }
            }
        }


        private static void cdb_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            // How do I get this info to the ViewModel?
        }
    }
}