private async void MetroWindow_Loaded(object sender, RoutedEventArgs e)
        {
            foreach (var item in affectedCourses)
            {
                if (item.StartDate == null || item.EndDate == null)
                {
                    await this.ShowMessageAsync("", "Cannot SHIFT classes with no Start Date.");

                    Close();
                }

                if (item.EndDate != null && item.EndDate <= DateTime.Now)
                {
                    await this.ShowMessageAsync("", "Cannot SHIFT, some classes are already over.");

                    Close();
                }
            }

            if (affectedCourses.Count == 1)
            {
                foreach (var item in affectedCourses[0].ShiftedDates)
                {
                    var val = new DayAndDate()
                    {
                        Date = item, Day = ((DayOfWeek)item.DayOfWeek).ToString()
                    };
                    listView_excluded.Items.Add(val);
                }
            }
        }
            public override bool Equals(object obj)
            {
                if (obj == null || this.GetType() != obj.GetType())
                {
                    return(false);
                }

                DayAndDate other = (DayAndDate)obj;

                return(other.Day == this.Day && other.Date == this.Date);
            }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (date_excluded.SelectedDate == null)
            {
                return;
            }

            var val = new DayAndDate()
            {
                Date = date_excluded.SelectedDate.Value, Day = ((DayOfWeek)date_excluded.SelectedDate.Value.DayOfWeek).ToString()
            };

            if (!listView_excluded.Items.Contains(val))
            {
                listView_excluded.Items.Add(val);
            }
        }
        private async void Button_Click_3(object sender, RoutedEventArgs e)
        {
            await this.ShowMessageAsync("", "This adds 7 days(Counting today) to the list.");

            var date = DateTime.Now;

            for (int i = 0; i < 7; i++)
            {
                var item = new DayAndDate()
                {
                    Date = date, Day = ((DayOfWeek)date.DayOfWeek).ToString()
                };
                if (!listView_excluded.Items.Contains(item))
                {
                    listView_excluded.Items.Add(item);
                }
                date = date.AddDays(1);
            }
        }