I have some backend code that needs to look at a collection of appointments and determine which ones are active now.
Are there any helper methods that would assist in determining this?  or Will I have to use the appointment.Start & appointment.End times in conjunction with the appointment.RecurrenceRule.Patten & appointment.RecurrenceRule.Exceptions to determine which ones are active.

Thanks
Craig.

<Window x:Class="DoubleClickEventFiredTwice.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" 
        xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WPF4" 
        Title="MainWindow" Height="350" Width="525" x:Name="window">
    <Grid>
        <telerik:RadGridView Margin="12" ShowGroupPanel="False" ItemsSource="{Binding Employees}"
                             AutoGenerateColumns="False" CanUserFreezeColumns="False" CanUserResizeColumns="False" IsReadOnly="True" 
                             SelectedItem="{Binding Path=SelectedEmployee, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" CanUserInsertRows="False" 
                             CanUserDeleteRows="False" DataLoadMode="Asynchronous" PreviewMouseDoubleClick="RadGridView_PreviewMouseDoubleClick">
            <telerik:RadGridView.Columns>
                <telerik:GridViewDataColumn Header="Name" DataMemberBinding="{Binding Name, Mode=TwoWay}" Width="1*" />
            </telerik:RadGridView.Columns>
            <telerik:RadGridView.ChildTableDefinitions>
                <telerik:GridViewTableDefinition>
                    <telerik:GridViewTableDefinition.Relation>
                        <telerik:PropertyRelation ParentPropertyName="Notes" />
                    </telerik:GridViewTableDefinition.Relation>
                </telerik:GridViewTableDefinition>
            </telerik:RadGridView.ChildTableDefinitions>
            <telerik:RadGridView.HierarchyChildTemplate>
                <DataTemplate>
                    <telerik:RadGridView x:Name="GridViewDetail" CanUserFreezeColumns="False" AutoGenerateColumns="False" ItemsSource="{Binding Notes}" 
                                                 ShowGroupPanel="False" IsReadOnly="True" CanUserInsertRows="False" 
                                                 SelectedItem="{Binding Mode=TwoWay, Path=DataContext.SelectedNote, RelativeSource={RelativeSource FindAncestor, AncestorType=Window, AncestorLevel=1}}" 
                                                 CanUserDeleteRows="False" DataLoadMode="Asynchronous" PreviewMouseDoubleClick="RadGridView_PreviewMouseDoubleClick">
                        <telerik:RadGridView.Columns>
                            <telerik:GridViewDataColumn DataMemberBinding="{Binding Text, Mode=TwoWay}" Header="Note" Width="200" />
                        </telerik:RadGridView.Columns>
                        <i:Interaction.Triggers>
                            <i:EventTrigger EventName="MouseDoubleClick">
                                <cmd:EventToCommand Command="{Binding Mode=OneWay, Path=DataContext.EditNoteCommand, RelativeSource={RelativeSource FindAncestor, AncestorType=Window, AncestorLevel=1}}"
                                                    PassEventArgsToCommand="True" />
                            </i:EventTrigger>
                        </i:Interaction.Triggers>
                    </telerik:RadGridView>
                </DataTemplate>
            </telerik:RadGridView.HierarchyChildTemplate>
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="MouseDoubleClick">
                    <cmd:EventToCommand Command="{Binding EditEmployeeCommand, Mode=OneWay}" PassEventArgsToCommand="True" />
                </i:EventTrigger>
            </i:Interaction.Triggers>
        </telerik:RadGridView>
    </Grid>
</Window>

using System;
using System.Linq;
using System.Windows;
using System.Windows.Input;
using Telerik.Windows.Controls;
using Telerik.Windows.Controls.GridView;
 
namespace DoubleClickEventFiredTwice
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();
 
            this.DataContext = new ViewModel();
        }
 
        private void RadGridView_PreviewMouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            var clicked = e.OriginalSource as UIElement;
 
            e.Handled = clicked == null || clicked.ParentOfType<GridViewRow>() == null;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Input;
using GalaSoft.MvvmLight.Command;
 
namespace DoubleClickEventFiredTwice
{
    public class ViewModel
    {
        public ViewModel()
        {
            this.EditEmployeeCommand = new RelayCommand<RoutedEventArgs>(
                args => this.EditEmployee(this.SelectedEmployee),
                args => this.SelectedEmployee != null);
 
            this.EditNoteCommand = new RelayCommand<RoutedEventArgs>(
                args => this.EditNote(this.SelectedNote),
                args => this.SelectedNote != null);
        }
 
        public IList<Employee> Employees
        {
            get
            {
                return new List<Employee>
                       {
                           new Employee { Name = "Hans Meier", Notes = new[]{ new Note { Text = "Hinweis 1"}, new Note { Text = "Hinweis 2"}   }},
                           new Employee { Name = "Klaus Schuster", Notes = new[]{ new Note { Text = "Hinweis 3"}, new Note { Text = "Hinweis 4"}   }}
                       };
            }
        }
 
        public Employee SelectedEmployee { get; set; }
 
        public Note SelectedNote { get; set; }
 
        public ICommand EditEmployeeCommand { get; private set; }
 
        public ICommand EditNoteCommand { get; private set; }
 
        public void EditEmployee(Employee item)
        {
            MessageBox.Show(item.Name);
        }
 
        public void EditNote(Note item)
        {
            MessageBox.Show(item.Text);
        }
    }
 
    public class Employee
    {
        public String Name { get; set; }
 
        public IList<Note> Notes { get; set; }
    }

    public class Note
    {
        public String Text { get; set; }
    }

}