DatePicker.DateValidationError Event
Occurs when Text is set to a value that cannot be interpreted as a date or when the date cannot be selected.
Assembly: PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
After the DateValidationError event occurs, if you set the DatePickerDateValidationErrorEventArgs.ThrowException property to true, one of the following exceptions is raised:
Exception type | Condition |
|---|---|
The text entered cannot be parsed to a valid date, and the exception is not suppressed. | |
The text entered parses to a date that is not selectable. |
The following example creates a DatePicker that displays the dates in August 2009 and specifies that each Saturday and Sunday is not selectable.
DatePicker datePickerWithBlackoutDates = new DatePicker(); datePickerWithBlackoutDates.DisplayDateStart = new DateTime(2009, 8, 1); datePickerWithBlackoutDates.DisplayDateEnd = new DateTime(2009, 8, 31); datePickerWithBlackoutDates.SelectedDate = new DateTime(2009, 8, 10); datePickerWithBlackoutDates.BlackoutDates.Add( new CalendarDateRange(new DateTime(2009, 8, 1), new DateTime(2009, 8, 2))); datePickerWithBlackoutDates.BlackoutDates.Add( new CalendarDateRange(new DateTime(2009, 8, 8), new DateTime(2009, 8, 9))); datePickerWithBlackoutDates.BlackoutDates.Add( new CalendarDateRange(new DateTime(2009, 8, 15), new DateTime(2009, 8, 16))); datePickerWithBlackoutDates.BlackoutDates.Add( new CalendarDateRange(new DateTime(2009, 8, 22), new DateTime(2009, 8, 23))); datePickerWithBlackoutDates.BlackoutDates.Add( new CalendarDateRange(new DateTime(2009, 8, 29), new DateTime(2009, 8, 30))); datePickerWithBlackoutDates.DateValidationError += new EventHandler<DatePickerDateValidationErrorEventArgs>(DatePicker_DateValidationError); // root is a Panel that is defined elsewhere. root.Children.Add(datePickerWithBlackoutDates);
<DatePicker Name="datePickerWithBlackoutDates" DisplayDateStart="8/1/09" DisplayDateEnd="8/31/09" SelectedDate="8/10/09" DateValidationError="DatePicker_DateValidationError"> <DatePicker.BlackoutDates> <CalendarDateRange Start="8/1/09" End="8/2/09"/> <CalendarDateRange Start="8/8/09" End="8/9/09"/> <CalendarDateRange Start="8/15/09" End="8/16/09"/> <CalendarDateRange Start="8/22/09" End="8/23/09"/> <CalendarDateRange Start="8/29/09" End="8/30/09"/> </DatePicker.BlackoutDates> </DatePicker>
The DatePicker handles the DateValidationError event, as shown in the following code. If the user enters a date that is not selectable, the example displays a message. If the user enters text that is not a valid date, an exception is thrown.
// If the text is a valid date, but a part of the // BlackoutDates collection, show a message. // If the text is not a valid date, thow an exception. private void DatePicker_DateValidationError(object sender, DatePickerDateValidationErrorEventArgs e) { DateTime newDate; DatePicker datePickerObj = sender as DatePicker; if (DateTime.TryParse(e.Text, out newDate)) { if (datePickerObj.BlackoutDates.Contains(newDate)) { MessageBox.Show(String.Format("The date, {0}, cannot be selected.", e.Text)); } } else { e.ThrowException = true; } }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.