/// <summary>
/// SelectedDateProperty property changed handler.
/// </summary>
/// <param name="d">DatePicker that changed its SelectedDate.</param>
/// <param name="e">DependencyPropertyChangedEventArgs.</param>
private static void OnSelectedDateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Collection <DateTime> addedItems = new Collection <DateTime>();
Collection <DateTime> removedItems = new Collection <DateTime>();
DateTime? addedDate;
DateTime? removedDate;
DatePicker datePicker = d as DatePicker;
Debug.Assert(datePicker != null);
addedDate = (DateTime?)e.NewValue;
removedDate = (DateTime?)e.OldValue;
if (addedDate.HasValue)
{
addedItems.Add(addedDate.Value);
}
if (removedDate.HasValue)
{
removedItems.Add(removedDate.Value);
}
if (addedDate != datePicker._calendar.SelectedDate)
{
datePicker._calendar.SelectedDate = addedDate;
}
if (datePicker.SelectedDate != null)
{
DateTime day = (DateTime)datePicker.SelectedDate;
//When the SelectedDateProperty change is done from OnTextPropertyChanged method, two-way binding breaks
//if BeginInvoke is not used:
datePicker.Dispatcher.BeginInvoke(delegate
{
datePicker._settingSelectedDate = true;
datePicker.Text = datePicker.DateTimeToString(day);
datePicker._settingSelectedDate = false;
datePicker.OnDateSelected(new SelectionChangedEventArgs(removedItems, addedItems));
});
//When DatePickerDisplayDateFlag is TRUE, the SelectedDate change is coming from the Calendar UI itself,
//so, we shouldn't change the DisplayDate since it will automatically be changed by the Calendar
if ((day.Month != datePicker.DisplayDate.Month || day.Year != datePicker.DisplayDate.Year) && !datePicker._calendar.DatePickerDisplayDateFlag)
{
datePicker.DisplayDate = day;
}
datePicker._calendar.DatePickerDisplayDateFlag = false;
}
else
{
datePicker._settingSelectedDate = true;
datePicker.SetWaterMarkText();
datePicker._settingSelectedDate = false;
datePicker.OnDateSelected(new SelectionChangedEventArgs(removedItems, addedItems));
}
}