WPF扩展器自动调整大小

Question

我有一个我作为模板创建的自定义扩展器：

<local:MultiplyConverter x:Key="multiplyConverter" />
        <ControlTemplate x:Key="AnimatedExpander" TargetType="{x:Type Expander}">
            <DockPanel>
                <ToggleButton x:Name="ExpanderButton" DockPanel.Dock="Top" Template="{StaticResource ExpanderButton}" Content="{TemplateBinding Header}" IsChecked="{Binding Path=IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" OverridesDefaultStyle="True">
                </ToggleButton>
                <ScrollViewer x:Name="ExpanderContentScrollView" DockPanel.Dock="Bottom" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Bottom">
                    <ScrollViewer.Tag>
                        <sys:Double>0.0</sys:Double>
                    </ScrollViewer.Tag>
                    <ScrollViewer.Height>
                        <MultiBinding Converter="{StaticResource multiplyConverter}">
                            <Binding Path="ActualHeight" ElementName="ExpanderContent"/>
                            <Binding Path="Tag" RelativeSource="{RelativeSource Self}" />
                        </MultiBinding>
                    </ScrollViewer.Height>
                    <ContentPresenter x:Name="ExpanderContent" ContentSource="Content" />
                </ScrollViewer>
            </DockPanel>
            <ControlTemplate.Triggers>
                <Trigger Property="IsExpanded" Value="True">
                    <Trigger.EnterActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetName="ExpanderContentScrollView" Storyboard.TargetProperty="Tag" To="1" Duration="0:0:0.3">
                                    <DoubleAnimation.EasingFunction>
                                        <CubicEase EasingMode="EaseOut"/>
                                    </DoubleAnimation.EasingFunction>
                                </DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </Trigger.EnterActions>
                    <Trigger.ExitActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetName="ExpanderContentScrollView" Storyboard.TargetProperty="Tag" To="0" Duration="0:0:0.3">
                                    <DoubleAnimation.EasingFunction>
                                        <CubicEase EasingMode="EaseOut"/>
                                    </DoubleAnimation.EasingFunction>
                                </DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </Trigger.ExitActions>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>

当我实际在网格中实例化Expander时，代码如下所示：

<Expander Template="{StaticResource AnimatedExpander}" ExpandDirection="Down" OverridesDefaultStyle="True" FontSize="11.0" Foreground="#CC000000" Header="Export Options" HorizontalAlignment="Stretch" VerticalAlignment="Bottom">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition></ColumnDefinition>
                    <ColumnDefinition></ColumnDefinition>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"></RowDefinition>
                    <RowDefinition></RowDefinition>
                </Grid.RowDefinitions>
                <Border Grid.Column="0" CornerRadius="0" Background="Transparent" Margin="10,0,10,0" BorderBrush="#FFAAAAAA" BorderThickness="0,0,0,0.5">
                    <ComboBox Grid.Column="0" ItemsSource="{Binding CurrentSlicerManager.Exporters}" DisplayMemberPath="Name" SelectedItem="{Binding CurrentSlicerManager.SelectedExporter, Mode=TwoWay}" Grid.Row="0" Margin="0,0,0,10"></ComboBox>
                </Border>
                <ContentControl Content="{Binding CurrentSlicerManager}" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2"></ContentControl>
            </Grid>
        </Expander>

正如您所看到的，我已将Expander中的内容绑定到ContentControl。 ContentControl使用DataTemplate来确定我应该将哪个.xaml加载到Expander中。所以，我有两个看起来像这样的DataTemplates：

<DataTemplate DataType="{x:Type MLC:MLRasterSlicerManager}">
            <local:MLRasterSlicerExportSettings></local:MLRasterSlicerExportSettings>
        </DataTemplate>

        <DataTemplate DataType="{x:Type MLC:MLVectorSlicerManager}">
            <local:MLVectorSlicerExportSettings></local:MLVectorSlicerExportSettings>
        </DataTemplate>

所以，我有两个.xaml文件（MLRasterSlicerExportSettings和MLVectorSlicerExportSettings）加载......这样可以正常工作。问题是这两个界面的高度不同。当我更改控制哪个文件加载到扩展器的组合框时，我希望扩展器自动调整大小。并且，当它首次加载具有较小高度的扩展器然后我切换它以加载具有较大高度值的扩展器时会发生这种情况...扩展器会自行调整大小以容纳更大的文件...但是如果我切换它回到较小的一个，然后它永远不会调整到适当的高度。它与最大文件保持相同的高度。任何人都可以推荐如何让这个扩展器自动调整大小到内容的大小？