从样式向 WPF DatePicker 添加清除按钮

Question

我可以在 DatePicker 上为日历控件添加清除按钮，但我想知道是否可以在 DatePicker 文本框上添加相同的按钮？

我有什么：

我想得到什么：

<DatePicker >
                <DatePicker.CalendarStyle>
                    <Style TargetType="Calendar">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate TargetType="{x:Type Calendar}">
                                    <Border BorderBrush="Black" BorderThickness="1">
                                        <StackPanel x:Name="PART_Root" HorizontalAlignment="Center" Background="LightBlue">
                                            <CalendarItem x:Name="PART_CalendarItem" 
                                                      BorderBrush="{TemplateBinding BorderBrush}" 
                                                      BorderThickness="{TemplateBinding BorderThickness}" 
                                                      Background="{TemplateBinding Background}" 
                                                      Style="{TemplateBinding CalendarItemStyle}" 
                                                      Height="Auto" Width="Auto"/>
                                            <Button Content="Clear Date"  Click="Button_Click"
                                                x:Name="PART_ClearButton"
                                                HorizontalAlignment="Center"
                                                VerticalAlignment="Center"
                                                Margin="2"/>
                                        </StackPanel>
                                    </Border>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>
                </DatePicker.CalendarStyle>
            </DatePicker>

Answer 1

看看DatePicker Styles and Templates。

修改 PART_Root：

看代码中的cmets，有修改的部分注明！

 <Grid x:Name="PART_Root" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*" />
                                <ColumnDefinition Width="Auto" />
                                <!--ADD ANOTHER COLUMN HERE-->
                                <ColumnDefinition Width="Auto" />
                            </Grid.ColumnDefinitions>

                            <!--CHANGE COLUMN=1 TO COLUMN =2-->
                            <Button x:Name="PART_Button"
                                    Grid.Column="2"
                Foreground="{TemplateBinding Foreground}"
                Focusable="False"
                HorizontalAlignment="Left"
                Margin="3,0,3,0"
                Grid.Row="0"
                Style="{StaticResource DropDownButtonStyle}"
                VerticalAlignment="Top" />

                            <!--//ADD THE BUTTON HERE-->
                            <Button Grid.Column="1" Content="X" Foreground="Red" Width="20" Height="20"/>

                            <DatePickerTextBox x:Name="PART_TextBox"
                           Grid.Column="0"
                           Foreground="{TemplateBinding Foreground}"
                           Focusable="{TemplateBinding Focusable}"
                           HorizontalContentAlignment="Stretch"
                           Grid.Row="0"
                           VerticalContentAlignment="Stretch" />
                            <Grid x:Name="PART_DisabledVisual"
              Grid.ColumnSpan="2"
              Grid.Column="0"
              IsHitTestVisible="False"
              Opacity="0"
              Grid.Row="0">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*" />
                                    <ColumnDefinition Width="Auto" />
                                </Grid.ColumnDefinitions>
                                <Rectangle Grid.Column="0"
                     Fill="#A5FFFFFF"
                     RadiusY="1"
                     Grid.Row="0"
                     RadiusX="1" />
                                <Rectangle Grid.Column="1"
                     Fill="#A5FFFFFF"
                     Height="18"
                     Margin="3,0,3,0"
                     RadiusY="1"
                     Grid.Row="0"
                     RadiusX="1"
                     Width="19" />
                                <Popup x:Name="PART_Popup"
                 AllowsTransparency="True"
                 Placement="Bottom"
                 PlacementTarget="{Binding ElementName=PART_TextBox}"
                 StaysOpen="False" />
                            </Grid>
                        </Grid>

结果将是：