Changing the string format of the WPF DatePicker

问题

I need to change the string format of the DatePickerTextBox in the WPF Toolkit DatePicker, to use hyphens instead of slashes for the seperators.

Is there a way to override this default culture or the display string format?

01-01-2010

回答1:

I have solved this problem with a help of this code. Hope it will help you all as well.

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

回答2:

It appears, as per Wonko's answer, that you cannot specify the Date format in Xaml format or by inheriting from the DatePicker.

I have put the following code into my View's constructor which overrides the ShortDateFormat for the current thread:

CultureInfo ci = CultureInfo.CreateSpecificCulture(CultureInfo.CurrentCulture.Name);
ci.DateTimeFormat.ShortDatePattern = "dd-MM-yyyy";
Thread.CurrentThread.CurrentCulture = ci;

回答3:

The WPF Toolkit DateTimePicker now has a Format property and a FormatString property. If you specify Custom as the format type, you can provide your own format string.

<wpftk:DateTimePicker
    Value="{Binding Path=StartTime, Mode=TwoWay}"
    Format="Custom"
    FormatString="MM/dd/yyyy hh:mmtt"/>

回答4:

The accepted answer (thanks @petrycol) put me on the right track, but I was getting another textbox border and background color within the actual date picker. Fixed it using the following code.

        <Style TargetType="{x:Type Control}" x:Key="DatePickerTextBoxStyle">
            <Setter Property="BorderThickness" Value="0"/>
            <Setter Property="VerticalAlignment" Value="Center"/>
            <Setter Property="Background" Value="{x:Null}"/>
        </Style>

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

回答5:

NOTE: This answer (originally written in 2010) is for earlier versions. See other answers for using a custom format with newer versions

Unfortunately, if you are talking about XAML, you are stuck with setting SelectedDateFormat to "Long" or "Short".

If you downloaded the source of the Toolkit along with the binaries, you can see how it is defined. Here are some of the highlights of that code:

DatePicker.cs

#region SelectedDateFormat

/// <summary>
/// Gets or sets the format that is used to display the selected date.
/// </summary>
public DatePickerFormat SelectedDateFormat
{
    get { return (DatePickerFormat)GetValue(SelectedDateFormatProperty); }
    set { SetValue(SelectedDateFormatProperty, value); }
}

/// <summary>
/// Identifies the SelectedDateFormat dependency property.
/// </summary>
public static readonly DependencyProperty SelectedDateFormatProperty =
    DependencyProperty.Register(
    "SelectedDateFormat",
    typeof(DatePickerFormat),
    typeof(DatePicker),
    new FrameworkPropertyMetadata(OnSelectedDateFormatChanged),
    IsValidSelectedDateFormat);

/// <summary>
/// SelectedDateFormatProperty property changed handler.
/// </summary>
/// <param name="d">DatePicker that changed its SelectedDateFormat.</param>
/// <param name="e">DependencyPropertyChangedEventArgs.</param>
private static void OnSelectedDateFormatChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    DatePicker dp = d as DatePicker;
    Debug.Assert(dp != null);

    if (dp._textBox != null)
    {
        // Update DatePickerTextBox.Text
        if (string.IsNullOrEmpty(dp._textBox.Text))
        {
            dp.SetWaterMarkText();
        }
        else
        {
            DateTime? date = dp.ParseText(dp._textBox.Text);

            if (date != null)
            {
                dp.SetTextInternal(dp.DateTimeToString((DateTime)date));
            }
        }
    }
}



#endregion SelectedDateFormat

private static bool IsValidSelectedDateFormat(object value)
{
    DatePickerFormat format = (DatePickerFormat)value;

    return format == DatePickerFormat.Long
        || format == DatePickerFormat.Short;
}

private string DateTimeToString(DateTime d)
{
    DateTimeFormatInfo dtfi = DateTimeHelper.GetCurrentDateFormat();

    switch (this.SelectedDateFormat)
    {
        case DatePickerFormat.Short:
            {
                return string.Format(CultureInfo.CurrentCulture, d.ToString(dtfi.ShortDatePattern, dtfi));
            }

        case DatePickerFormat.Long:
            {
                return string.Format(CultureInfo.CurrentCulture, d.ToString(dtfi.LongDatePattern, dtfi));
            }
    }      

    return null;
}

DatePickerFormat.cs

public enum DatePickerFormat
{
    /// <summary>
    /// Specifies that the date should be displayed 
    /// using unabbreviated days of the week and month names.
    /// </summary>
    Long = 0,

    /// <summary>
    /// Specifies that the date should be displayed 
    ///using abbreviated days of the week and month names.
    /// </summary>
    Short = 1
}

回答6:

XAML

 <DatePicker x:Name="datePicker" />

C#

var date = Convert.ToDateTime(datePicker.Text).ToString("yyyy/MM/dd");

put what ever format you want in ToString("") for example ToString("dd MMM yyy") and output format will be 7 Jun 2017

回答7:

Converter class:

public class DateFormat : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value == null) return null;
        return ((DateTime)value).ToString("dd-MMM-yyyy");
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

wpf tag

<DatePicker Grid.Column="3" SelectedDate="{Binding DateProperty, Converter={StaticResource DateFormat}}" Margin="5"/>

Hope it helps

回答8:

Format exhibited depending on the location but this can be avoided by writing this:

  ValueStringFormat="{}{0:MM'-'yy}" />

And you will be happy!(dd'-'MM'-'yyy)

来源：https://stackoverflow.com/questions/3819832/changing-the-string-format-of-the-wpf-datepicker