.net 如何在WPF应用程序中更改DateTimePicker的格式（如dd/MMM/yyyy）

我想更改在WPF应用程序的DateTimePicker中选择的日期格式。通常，日期时间格式存储在资源文件中，因为这将有助于应用程序的国际化

您可以从资源文件中选择格式并使用

ToString（日期格式）

在您的情况下，您可能需要使用

dateTimePicker.SelectedDate.ToString("dd-MMM-yyyy");

在XAML中：

<toolkit:DatePicker SelectedDateFormat="Long" />

或

---

我正在紧急处理这个问题。我找到了一个简单的方法来执行这种自定义格式，我希望这对您有所帮助。您需要做的第一件事是在XAML中对当前日期选择器应用特定样式，如下所示：

<DatePicker.Resources>
    <Style TargetType="{x:Type DatePickerTextBox}">
        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <TextBox x:Name="PART_TextBox" Width="113" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" Text="{Binding Path=SelectedDate,Converter={StaticResource DateTimeFormatter},RelativeSource={RelativeSource AncestorType={x:Type DatePicker}},ConverterParameter=dd-MMM-yyyy}" BorderBrush="{DynamicResource BaseBorderBrush}" />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</DatePicker.Resources>

---

我希望这对你有帮助。请让我知道任何问题或改进建议。

对于我来说，更改环境以更改

DatePicker

格式（如

Thread.CurrentCulture

）不是一个好主意。 当然，您可以创建从

DatePicker

派生的

控件

，并实现类似

格式

的依赖项属性，但这需要花费太多的精力

我找到的简单而优雅的解决方案不是将值绑定到

SelectedDate

本身，而是绑定到一些未使用的属性（我为此使用了

ToolTip

属性），并在更改SelectedDate时更新此属性

单向绑定的C#实现如下所示：

    DatePicker datePicker = new DatePicker();
    datePicker.SetBinding(ToolTipProperty, "Date");
    datePicker.SelectedDateChanged += (s, ea) =>
        {
            DateTime? date = datePicker.SelectedDate;
            string value = date != null ? date.Value.ToString("yyyy-MM-dd") : null;
            datePicker.ToolTip = value;
        };

XAML+C#应该是这样的：

    DatePicker datePicker = new DatePicker();
    datePicker.SetBinding(ToolTipProperty, "Date");
    datePicker.SelectedDateChanged += (s, ea) =>
        {
            DateTime? date = datePicker.SelectedDate;
            string value = date != null ? date.Value.ToString("yyyy-MM-dd") : null;
            datePicker.ToolTip = value;
        };

XAML：

---

对于双向实现句柄

ToolTipChanged

事件，更新

SelectedDate

的方法与更新

SelectedDate的方法相同，感谢@Fernando García的支持

我已经为DatePicker编写了一个DateFormat附加属性，它允许您提供一个用于显示和输入的格式字符串

对于输入，它将尝试使用提供的格式进行解析，然后返回到使用当前区域性的格式进行解析

问题格式的用法示例：

<DatePicker my:DatePickerDateFormat.DateFormat="dd/MMM/yyyy"/>



DateFormat附加属性是：

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))
            };
        var textBox = GetTemplateTextBox(datePicker);
        textBox.SetBinding(TextBox.TextProperty, binding);

        textBox.PreviewKeyDown -= TextBoxOnPreviewKeyDown;
        textBox.PreviewKeyDown += TextBoxOnPreviewKeyDown;

        datePicker.CalendarOpened -= DatePickerOnCalendarOpened;
        datePicker.CalendarOpened += DatePickerOnCalendarOpened;
    }

    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;
        }
    }
}

公共类DatePickerDateFormat
{
公共静态只读DependencyProperty DateFormatProperty=
DependencyProperty.RegisterAttached（“DateFormat”、typeof（string）、typeof（DatePickerDateFormat），
新属性元数据（OnDateFormatChanged））；
公共静态字符串GetDateFormat（DependencyObject dobj）
{
返回（字符串）dobj.GetValue（DateFormatProperty）；
}
公共静态void SetDateFormat（DependencyObject dobj，字符串值）
{
dobj.SetValue（DateFormatProperty，value）；
}
私有静态void OnDateFormatChanged（DependencyObject dobj、DependencyPropertyChangedEventArgs e）
{
var datePicker=（datePicker）dobj；
Application.Current.Dispatcher.BeginInvoke(
DispatcherPriority.Loaded，新操作（ApplyDateFormat），日期选择器；
}
私有静态void ApplyDateFormat（日期选择器日期选择器）
{
变量绑定=新绑定（“SelectedDate”）
{
RelativeSource=new RelativeSource{AncestorType=typeof（日期选择器）}，
Converter=新的DatePickerDateTimeConverter（），
ConverterParameter=新元组（日期选择器，GetDateFormat（日期选择器））
};
var textBox=GetTemplateTextBox（日期选择器）；
textBox.SetBinding（textBox.TextProperty，binding）；
textBox.PreviewKeyDown-=TextBoxOnPreviewKeyDown；
textBox.PreviewKeyDown+=TextBoxOnPreviewKeyDown；
datePicker.CalendarOpen-=DatePickerOnCalendarOpen；
datePicker.CalendarOpen+=DatePickerOnCalendarOpen；
}
私有静态文本框GetTemplateTextBox（控件）
{
control.ApplyTemplate（）；
return（TextBox）control.Template.FindName（“PART_TextBox”，control）；
}
私有静态void TextBoxOnPreviewKeyDown（对象发送方，KeyEventArgs e）
{
if（e.Key！=Key.Return）
返回；
/*DatePicker订阅其文本框的KeyDown事件，以便在Key.Return为时设置其SelectedDate
*当这种情况发生时，其文本将是其内部日期解析的结果，直到
*失去焦点或选择了另一个日期。解决方法是停止按键事件冒泡
*和处理设置DatePicker.SelectedDate*/
e、 已处理=正确；
var textBox=（textBox）发送方；
var datePicker=（datePicker）textBox.TemplatedParent；
var dateStr=textBox.Text；
var formatStr=GetDateFormat（日期选择器）；
datePicker.SelectedDate=DatePickerDateTimeConverter.StringToDateTime（datePicker，formatStr，dateStr）；
}
私有静态无效日期选择器日历已打开（对象发送方，RoutedEventArgs e）
{
/*当DatePicker的文本框没有焦点且其日历通过单击其日历按钮打开时
*它的文本将是内部日期解析的结果，直到它的文本框被聚焦和另一个
*已选择日期。解决方法是在打开该字符串时设置该字符串*/
var datePicker=（datePicker）发送方；
var textBox=GetTemplateTextBox（日期选择器）；
var formatStr=GetDateFormat（日期选择器）；
textBox.Text=DatePickerDateTimeConverter.DateTimeToString（formatStr，datePicker.SelectedDate）；
}
私有类DatePickerDateTimeConverter:IValueConverter
{
公共对象转换（对象值、类型targetType、对象参数、CultureInfo区域性）
{
var formatStr=（（元组）参数）；
var selectedDate=（日期时间？）值；
返回日期时间字符串（formatStr，selectedDate）；
}
公共对象转换回（对象值、类型targetType、对象参数、CultureInfo区域性）
{
var tupleParam=（（Tuple）参数）；
var dateStr=（字符串）值；
返回StringToDateTime（tupleParam.Item1、tupleParam.Item2、dat
    DatePicker datePicker = new DatePicker();
    datePicker.SetBinding(ToolTipProperty, "Date");
    datePicker.SelectedDateChanged += (s, ea) =>
        {
            DateTime? date = datePicker.SelectedDate;
            string value = date != null ? date.Value.ToString("yyyy-MM-dd") : null;
            datePicker.ToolTip = value;
        };

<DatePicker ToolTip="{Binding Date Mode=TwoWay}"
            SelectedDateChanged="DatePicker_SelectedDateChanged"/>

private void DatePicker_SelectedDateChanged(object sender, EventArgs ea)
{
    DatePicker datePicker = (DatePicker)sender;
    DateTime? date = datePicker.SelectedDate;
    string value = date != null ? date.Value.ToString("yyyy-MM-dd") : null;
    datePicker.ToolTip = value;
}

<DatePicker my:DatePickerDateFormat.DateFormat="dd/MMM/yyyy"/>

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))
            };
        var textBox = GetTemplateTextBox(datePicker);
        textBox.SetBinding(TextBox.TextProperty, binding);

        textBox.PreviewKeyDown -= TextBoxOnPreviewKeyDown;
        textBox.PreviewKeyDown += TextBoxOnPreviewKeyDown;

        datePicker.CalendarOpened -= DatePickerOnCalendarOpened;
        datePicker.CalendarOpened += DatePickerOnCalendarOpened;
    }

    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;
        }
    }
}

 <Style TargetType="{x:Type DatePickerTextBox}">
     <Setter Property="VerticalContentAlignment" Value="Center"/>
     <Setter Property="Control.Template">
         <Setter.Value>
             <ControlTemplate>
                 <TextBox x:Name="PART_TextBox"
            Text="{Binding Path=SelectedDate, StringFormat='dd.MM.yyyy', 
            RelativeSource={RelativeSource AncestorType={x:Type DatePicker}}}" />
             </ControlTemplate>
         </Setter.Value>
     </Setter>
 </Style>

    private void UserControl_Loaded(object sender, RoutedEventArgs e)
    {
      DateLabel.Content = Convert.ToDateTime(datePicker1.Text).ToString("dd-MM-yyyy");
    }