WPF Datepicker样式

WPF 的 DatePicker 控件的样式可以通过自定义控件模板来实现，以下是一些示例代码：

1. 在XAML文件中定义DatePicker的控件模板：

<Style TargetType="DatePicker">
    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}" />
    <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}" />
    <Setter Property="BorderBrush" Value="{DynamicResource {x:Static SystemColors.InactiveBorderBrushKey}}" />
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="Padding" Value="2,0,0,0" />
    <Setter Property="HorizontalAlignment" Value="Left" />
    <Setter Property="VerticalAlignment" Value="Top" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="DatePicker">
                <Grid>
                    <Grid.Resources>
                        <SolidColorBrush x:Key="DisabledBrush" Color="#A5FFFFFF" />
                        <ControlTemplate x:Key="DropDownButtonTemplate" TargetType="Button">
                            <Grid>
                                <VisualStateManager.VisualStateGroups>
                                    <VisualStateGroup x:Name="CommonStates">
                                        <VisualState x:Name="Normal" />
                                        <VisualState x:Name="MouseOver">
                                            <Storyboard>
                                                <ColorAnimation Duration="0" To="#FF448DCA" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="arrow" />
                                            </Storyboard>
                                        </VisualState>
                                        <VisualState x:Name="Pressed">
                                            <Storyboard>
                                                <ColorAnimation Duration="0" To="#FF2C628B" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="arrow" />
                                            </Storyboard>
                                        </VisualState>
                                        <VisualState x:Name="Disabled">
                                            <Storyboard>
                                                <DoubleAnimation Duration="0" To="0.5" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="arrow" />
                                            </Storyboard>
                                        </VisualState>
                                    </VisualStateGroup>
                                </VisualStateManager.VisualStateGroups>
                                <Grid Background="Transparent">
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="*" />
                                        <ColumnDefinition Width="Auto" />
                                    </Grid.ColumnDefinitions>
                                    <Border x:Name="Background" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" CornerRadius="2" />
                                    <Border Grid.Column="0" Margin="1" Background="White" CornerRadius="2,0,0,2" />
                                    <Path x:Name="arrow" Grid.Column="1" Fill="#FF606060" HorizontalAlignment="Center" VerticalAlignment="Center" Data="M 0 0 L 4 4 L 8 0 Z">
                                        <Path.RenderTransform>
                                            <ScaleTransform ScaleX="1" ScaleY="1" />
                                        </Path.RenderTransform>
                                    </Path>
                                    <Popup x:Name="Popup" Placement="Bottom" IsOpen="{TemplateBinding IsDropDownOpen}" AllowsTransparency="True" Focusable="False" PopupAnimation="Slide">
                                        <Grid x:Name="DropDown" SnapsToDevicePixels="True" MinWidth="{TemplateBinding ActualWidth}" MaxHeight="{TemplateBinding MaxDropDownHeight}">
                                            <Border x:Name="DropDownBorder" Background="White" BorderThickness="1" BorderBrush="#FF707070" />
                                            <ScrollViewer>
                                                <StackPanel>
                                                    <DatePicker x:Name="PART_TextBox" Style="{x:Null}" />
                                                </StackPanel>
                                            </ScrollViewer>
                                        </Grid>
                                    </Popup>
                                </Grid>
                            </Grid>
                        </ControlTemplate>
                    </Grid.Resources>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Focusable="False" HorizontalContentAlignment="Stretch" IsReadOnly="True" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch" />
                    <Button Grid.Column="1" Focusable="False" IsEnabled="{TemplateBinding IsDropDownOpen}" Template="{StaticResource DropDownButtonTemplate}" />
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

2. 在使用DatePicker时，直接使用该控件模板即可：

<DatePicker Style="{StaticResource {x:Type DatePicker}}" />

以上是一些示例代码，你可以根据自己的需求自定义DatePicker的样式。