Question

A small demo program is included below. To reproduce the problem, select a date and click the “BlackoutDate” button. On my system I get an ArgumentOutOfRange exception.

Any suggestions on how to fix this?

XAML:

<Window x:Class="CalendarBlackoutDate.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <Calendar Name="calendar"/>
        <Button Name="blackoutDateButton" Content="BlackoutDate" Click="blackoutDateButton_Click"/>
    </StackPanel>
</Window>

C#:

using System.Windows;
using System.Windows.Controls;

namespace CalendarBlackoutDate
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void blackoutDateButton_Click(object sender, RoutedEventArgs e)
        {
            calendar.BlackoutDates.Add(
                new CalendarDateRange(
                    calendar.SelectedDate.Value));
        }
    }
}

Answer 1

Same calendar for the selected date as the blackout?? Selected date cannot be blackout date.

 calendar1.BlackoutDates.Add(
            new CalendarDateRange(
                calendar2.SelectedDate.Value));

<Calendar Name="calendar1"/>
<Calendar Name="calendar2"/>

If one calendar

if (calendar1.SelectedDate == null) return;
DateTime dtBO = (DateTime)calendar1.SelectedDate;
calendar1.SelectedDate = null;
calendar1.BlackoutDates.Add(new CalendarDateRange(dtBO));