1. 배경
기본 DatePicker는
날짜까지 선택이 가능하다.
구체적인 날짜까지 선택하지 않고 년/월만 선택할 수 있는 DatePicker를 만들기 위해 열심히 구글 검색을 해본 결과 DatePikcer를 새로 정의해서 사용하는 방법을 StackOverflow에서 찾을 수 있었다.
2. 개발환경
- VisualStudio 2022 / WPF 애플리케이션(.NET Framework 4.7.2)
3. 내용
- DatePickerCalendar.cs 추가
- DataPickerCalendar.cs에 내용 작성
public class DatePickerCalendar
{
public static readonly DependencyProperty IsMonthYearProperty =
DependencyProperty.RegisterAttached("IsMonthYear", typeof(bool), typeof(DatePickerCalendar),
new PropertyMetadata(OnIsMonthYearChanged));
public static bool GetIsMonthYear(DependencyObject dobj)
{
return (bool)dobj.GetValue(IsMonthYearProperty);
}
public static void SetIsMonthYear(DependencyObject dobj, bool value)
{
dobj.SetValue(IsMonthYearProperty, value);
}
private static void OnIsMonthYearChanged(DependencyObject dobj, DependencyPropertyChangedEventArgs e)
{
var datePicker = (DatePicker)dobj;
Application.Current.Dispatcher
.BeginInvoke(DispatcherPriority.Loaded,
new Action<DatePicker, DependencyPropertyChangedEventArgs>(SetCalendarEventHandlers),
datePicker, e);
}
private static void SetCalendarEventHandlers(DatePicker datePicker, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue == e.OldValue)
return;
if ((bool)e.NewValue)
{
datePicker.CalendarOpened += DatePickerOnCalendarOpened;
datePicker.CalendarClosed += DatePickerOnCalendarClosed;
}
else
{
datePicker.CalendarOpened -= DatePickerOnCalendarOpened;
datePicker.CalendarClosed -= DatePickerOnCalendarClosed;
}
}
private static void DatePickerOnCalendarOpened(object sender, RoutedEventArgs routedEventArgs)
{
var calendar = GetDatePickerCalendar(sender);
calendar.DisplayMode = CalendarMode.Year;
calendar.DisplayModeChanged += CalendarOnDisplayModeChanged;
}
private static void DatePickerOnCalendarClosed(object sender, RoutedEventArgs routedEventArgs)
{
var datePicker = (DatePicker)sender;
var calendar = GetDatePickerCalendar(sender);
datePicker.SelectedDate = calendar.SelectedDate;
calendar.DisplayModeChanged -= CalendarOnDisplayModeChanged;
}
private static void CalendarOnDisplayModeChanged(object sender, CalendarModeChangedEventArgs e)
{
var calendar = (System.Windows.Controls.Calendar)sender;
if (calendar.DisplayMode != CalendarMode.Month)
return;
calendar.SelectedDate = GetSelectedCalendarDate(calendar.DisplayDate);
var datePicker = GetCalendarsDatePicker(calendar);
datePicker.IsDropDownOpen = false;
}
private static System.Windows.Controls.Calendar GetDatePickerCalendar(object sender)
{
var datePicker = (DatePicker)sender;
var popup = (Popup)datePicker.Template.FindName("PART_Popup", datePicker);
return ((System.Windows.Controls.Calendar)popup.Child);
}
private static DatePicker GetCalendarsDatePicker(FrameworkElement child)
{
var parent = (FrameworkElement)child.Parent;
if (parent.Name == "PART_Root")
return (DatePicker)parent.TemplatedParent;
return GetCalendarsDatePicker(parent);
}
private static DateTime? GetSelectedCalendarDate(DateTime? selectedDate)
{
if (!selectedDate.HasValue)
return null;
return new DateTime(selectedDate.Value.Year, selectedDate.Value.Month, 1);
}
}
public class DatePickerDateFormat
{
public static readonly DependencyProperty DateFormatProperty =
DependencyProperty.RegisterAttached("DateFormat", typeof(string), typeof(DatePickerDateFormat),
new PropertyMetadata(OnDateFormatChanged));
public static string GetDateFormat(DependencyObject dobj)
{
return (string)dobj.GetValue(DateFormatProperty);
}
public static void SetDateFormat(DependencyObject dobj, string value)
{
dobj.SetValue(DateFormatProperty, value);
}
private static void OnDateFormatChanged(DependencyObject dobj, DependencyPropertyChangedEventArgs e)
{
var datePicker = (DatePicker)dobj;
Application.Current.Dispatcher.BeginInvoke(
DispatcherPriority.Loaded, new Action<DatePicker>(ApplyDateFormat), datePicker);
}
private static void ApplyDateFormat(DatePicker datePicker)
{
var binding = new Binding("SelectedDate")
{
RelativeSource = new RelativeSource { AncestorType = typeof(DatePicker) },
Converter = new DatePickerDateTimeConverter(),
ConverterParameter = new Tuple<DatePicker, string>(datePicker, GetDateFormat(datePicker)),
StringFormat = GetDateFormat(datePicker) // This is also new but didnt seem to help
};
var textBox = GetTemplateTextBox(datePicker);
textBox.SetBinding(TextBox.TextProperty, binding);
textBox.PreviewKeyDown -= TextBoxOnPreviewKeyDown;
textBox.PreviewKeyDown += TextBoxOnPreviewKeyDown;
var dropDownButton = GetTemplateButton(datePicker);
datePicker.CalendarOpened -= DatePickerOnCalendarOpened;
datePicker.CalendarOpened += DatePickerOnCalendarOpened;
// Handle Dropdownbutton PreviewMouseUp to prevent issue of flickering textboxes
dropDownButton.PreviewMouseUp -= DropDownButtonPreviewMouseUp;
dropDownButton.PreviewMouseUp += DropDownButtonPreviewMouseUp;
}
private static ButtonBase GetTemplateButton(DatePicker datePicker)
{
return (ButtonBase)datePicker.Template.FindName("PART_Button", datePicker);
}
/// <summary>
/// Prevents a bug in the DatePicker, where clicking the Dropdown open button results in Text being set to default formatting regardless of StringFormat or binding overrides
/// </summary>
private static void DropDownButtonPreviewMouseUp(object sender, MouseButtonEventArgs e)
{
var fe = sender as FrameworkElement;
if (fe == null) return;
var datePicker = fe.TryFindParent<DatePicker>();
if (datePicker == null || datePicker.SelectedDate == null) return;
var dropDownButton = GetTemplateButton(datePicker);
// Dropdown button was clicked
if (e.OriginalSource == dropDownButton && datePicker.IsDropDownOpen == false)
{
// Open dropdown
datePicker.SetCurrentValue(DatePicker.IsDropDownOpenProperty, true);
// Mimic everything else in the standard DatePicker dropdown opening *except* setting textbox value
datePicker.SetCurrentValue(DatePicker.DisplayDateProperty, datePicker.SelectedDate.Value);
// Important otherwise calendar does not work
dropDownButton.ReleaseMouseCapture();
// Prevent datePicker.cs from handling this event
e.Handled = true;
}
}
private static TextBox GetTemplateTextBox(Control control)
{
control.ApplyTemplate();
return (TextBox)control?.Template?.FindName("PART_TextBox", control);
}
private static void TextBoxOnPreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key != Key.Return)
return;
/* DatePicker subscribes to its TextBox's KeyDown event to set its SelectedDate if Key.Return was
* pressed. When this happens its text will be the result of its internal date parsing until it
* loses focus or another date is selected. A workaround is to stop the KeyDown event bubbling up
* and handling setting the DatePicker.SelectedDate. */
e.Handled = true;
var textBox = (TextBox)sender;
var datePicker = (DatePicker)textBox.TemplatedParent;
var dateStr = textBox.Text;
var formatStr = GetDateFormat(datePicker);
datePicker.SelectedDate = DatePickerDateTimeConverter.StringToDateTime(datePicker, formatStr, dateStr);
}
private static void DatePickerOnCalendarOpened(object sender, RoutedEventArgs e)
{
/* When DatePicker's TextBox is not focused and its Calendar is opened by clicking its calendar button
* its text will be the result of its internal date parsing until its TextBox is focused and another
* date is selected. A workaround is to set this string when it is opened. */
var datePicker = (DatePicker)sender;
var textBox = GetTemplateTextBox(datePicker);
var formatStr = GetDateFormat(datePicker);
textBox.Text = DatePickerDateTimeConverter.DateTimeToString(formatStr, datePicker.SelectedDate);
}
private class DatePickerDateTimeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var formatStr = ((Tuple<DatePicker, string>)parameter).Item2;
var selectedDate = (DateTime?)value;
return DateTimeToString(formatStr, selectedDate);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
var tupleParam = ((Tuple<DatePicker, string>)parameter);
var dateStr = (string)value;
return StringToDateTime(tupleParam.Item1, tupleParam.Item2, dateStr);
}
public static string DateTimeToString(string formatStr, DateTime? selectedDate)
{
return selectedDate.HasValue ? selectedDate.Value.ToString(formatStr) : null;
}
public static DateTime? StringToDateTime(DatePicker datePicker, string formatStr, string dateStr)
{
DateTime date;
var canParse = DateTime.TryParseExact(dateStr, formatStr, CultureInfo.CurrentCulture,
DateTimeStyles.None, out date);
if (!canParse)
canParse = DateTime.TryParse(dateStr, CultureInfo.CurrentCulture, DateTimeStyles.None, out date);
return canParse ? date : datePicker.SelectedDate;
}
}
}
public static class FEExten
{
/// <summary>
/// Finds a parent of a given item on the visual tree.
/// </summary>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="child">A direct or indirect child of the
/// queried item.</param>
/// <returns>The first parent item that matches the submitted
/// type parameter. If not matching item can be found, a null
/// reference is being returned.</returns>
public static T TryFindParent<T>(this DependencyObject child)
where T : DependencyObject
{
//get parent item
DependencyObject parentObject = GetParentObject(child);
//we've reached the end of the tree
if (parentObject == null) return null;
//check if the parent matches the type we're looking for
T parent = parentObject as T;
if (parent != null)
{
return parent;
}
else
{
//use recursion to proceed with next level
return TryFindParent<T>(parentObject);
}
}
/// <summary>
/// This method is an alternative to WPF's
/// <see cref="VisualTreeHelper.GetParent"/> method, which also
/// supports content elements. Keep in mind that for content element,
/// this method falls back to the logical tree of the element!
/// </summary>
/// <param name="child">The item to be processed.</param>
/// <returns>The submitted item's parent, if available. Otherwise
/// null.</returns>
public static DependencyObject GetParentObject(this DependencyObject child)
{
if (child == null) return null;
//handle content elements separately
ContentElement contentElement = child as ContentElement;
if (contentElement != null)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if (parent != null) return parent;
FrameworkContentElement fce = contentElement as FrameworkContentElement;
return fce != null ? fce.Parent : null;
}
//also try searching for parent in framework elements (such as DockPanel, etc)
FrameworkElement frameworkElement = child as FrameworkElement;
if (frameworkElement != null)
{
DependencyObject parent = frameworkElement.Parent;
if (parent != null) return parent;
}
//if it's not a ContentElement/FrameworkElement, rely on VisualTreeHelper
return VisualTreeHelper.GetParent(child);
}
}- xaml에서의 사용
<DatePicker tk:DatePickerCalendar.IsMonthYear="True" tk:DatePickerDateFormat.DateFormat="yyyy-MMM" Text="yyyy-MMM" SelectedDate="{Binding SEL_MONTH}" Grid.Column="1" Margin="0,0,5,0" VerticalAlignment="Center"/>앞의 tk는 DatePickerCalendar.cs가 작성된 폴더이다.
namespace에 추가하면된다.
선택한 년/월의 Binding은 CommandParameter를 사용한다...
4. 결과
5. 참조
안뇽하세용