我为自定义扩展器下载了一些代码，并将其更改为我想要的方式，但有一个例外。扩展后，高度硬编码为100。我需要它像普通的扩展器一样，并设置高度以容纳控件中的任何内容。这是与之相关的XAML，你会注意到Value =“100”，我试过Auto但是我被迫输入一个双倍的值，因为它是目前的。有什么想法吗？
<Style TargetType="{x:Type Expander}" x:Key="MyExpander">
<Setter Property="Foreground" Value="{DynamicResource TextBrush}" />
<Setter Property="Background" Value="Transparent" />
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Setter Property="VerticalContentAlignment" Value="Stretch" />
<Setter Property="BorderBrush" Value="Transparent" />
<Setter Property="BorderThickness" Value="1" />
<!--<Setter Property="HeaderTemplate" Value="{StaticResource titleText}"/>-->
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Expander}">
<ControlTemplate.Resources>
<Storyboard x:Key="strbExpand">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="border" Storyboard.TargetProperty="(FrameworkElement.Height)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
<SplineDoubleKeyFrame KeyTime="00:00:00.1200000" Value="100"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
<Storyboard x:Key="strbCollapse">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="border" Storyboard.TargetProperty="(FrameworkElement.Height)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="100"/>
<SplineDoubleKeyFrame KeyTime="00:00:00.1200000" Value="0"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</ControlTemplate.Resources>
<Border SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,1" CornerRadius="3" >
<DockPanel x:Name="dockPanel">
<ToggleButton FontFamily="{TemplateBinding FontFamily}" FontSize="{TemplateBinding FontSize}" FontStretch="{TemplateBinding FontStretch}" FontStyle="{TemplateBinding FontStyle}" FontWeight="{TemplateBinding FontWeight}"
Foreground="{TemplateBinding Foreground}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}" Margin="1,1,1,0" MinHeight="0" MinWidth="0" x:Name="HeaderSite" Style="{StaticResource ExpanderDownHeaderStyle}"
Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}"
ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" DockPanel.Dock="Top" />
<Border Background="{DynamicResource ShadeBrush}" BorderBrush="{DynamicResource NormalBorderBrush}" BorderThickness="1,0,1,1" CornerRadius="3,3,3,3" x:Name="border" Margin="1,1,1,1" Height="0" >
<ContentPresenter x:Name="ExpandSite" Focusable="false" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="1,1,1,1" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" DockPanel.Dock="Bottom" />
</Border>
</DockPanel>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="true">
<Trigger.EnterActions>
<BeginStoryboard Storyboard="{StaticResource strbExpand}"/>
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard Storyboard="{StaticResource strbCollapse}"/>
</Trigger.ExitActions>
</Trigger>
<Trigger Property="ExpandDirection" Value="Down">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Bottom" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Top" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderDownHeaderStyle}" />
</Trigger>
<!--<Trigger Property="ExpandDirection" Value="Right">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderRightHeaderStyle}" />
</Trigger>
<Trigger Property="ExpandDirection" Value="Up">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderUpHeaderStyle}" />
</Trigger>
<Trigger Property="ExpandDirection" Value="Left">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderLeftHeaderStyle}" />
</Trigger>-->
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
答案 0 :(得分：2)
认为您可以通过组合Height属性调整Tag来实现此目的。
类似的东西：
<Style x:Key="MyExpander"
TargetType="{x:Type Expander}">
<Setter Property="Foreground"
Value="{DynamicResource TextBrush}" />
<Setter Property="Background"
Value="Transparent" />
<Setter Property="HorizontalContentAlignment"
Value="Stretch" />
<Setter Property="VerticalContentAlignment"
Value="Stretch" />
<Setter Property="BorderBrush"
Value="Transparent" />
<Setter Property="BorderThickness"
Value="1" />
<!-- <Setter Property="HeaderTemplate" Value="{StaticResource titleText}"/> -->
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Expander}">
<ControlTemplate.Resources>
<Storyboard x:Key="strbExpand">
<DoubleAnimation Duration="0:0:0.12"
Storyboard.TargetName="border"
Storyboard.TargetProperty="Tag"
To="1" />
</Storyboard>
<Storyboard x:Key="strbCollapse">
<DoubleAnimation Duration="0:0:0.12"
Storyboard.TargetName="border"
Storyboard.TargetProperty="Tag"
To="0" />
</Storyboard>
<local:VariableHeightAnimationConverter x:Key="VariableHeightAnimationConverter" />
</ControlTemplate.Resources>
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="1,1,1,1"
CornerRadius="3"
SnapsToDevicePixels="true">
<DockPanel x:Name="dockPanel">
<ToggleButton x:Name="HeaderSite"
MinWidth="0"
MinHeight="0"
Margin="1,1,1,0"
HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
Content="{TemplateBinding Header}"
ContentTemplate="{TemplateBinding HeaderTemplate}"
ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
DockPanel.Dock="Top"
FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}"
FontFamily="{TemplateBinding FontFamily}"
FontSize="{TemplateBinding FontSize}"
FontStretch="{TemplateBinding FontStretch}"
FontStyle="{TemplateBinding FontStyle}"
FontWeight="{TemplateBinding FontWeight}"
Foreground="{TemplateBinding Foreground}"
IsChecked="{Binding Path=IsExpanded,
Mode=TwoWay,
RelativeSource={RelativeSource TemplatedParent}}"
Padding="{TemplateBinding Padding}"
Style="{StaticResource ExpanderDownHeaderStyle}" />
<Border x:Name="border"
Margin="1,1,1,1"
Background="{DynamicResource ShadeBrush}"
BorderBrush="{DynamicResource NormalBorderBrush}"
BorderThickness="1,0,1,1"
CornerRadius="3,3,3,3">
<Border.Tag>
<sys:Double>0.0</sys:Double>
</Border.Tag>
<Border.Height>
<MultiBinding Converter="{StaticResource VariableHeightAnimationConverter}">
<Binding ElementName="ExpandSite"
Path="ActualHeight" />
<Binding Path="Tag"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</Border.Height>
<!-- ScrollViewer to allow us to compute the actual required height of the ContentPresenter -->
<ScrollViewer HorizontalScrollBarVisibility="Hidden"
VerticalScrollBarVisibility="Hidden">
<ContentPresenter x:Name="ExpandSite"
Margin="1,1,1,1"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
DockPanel.Dock="Bottom"
Focusable="false" />
</ScrollViewer>
</Border>
</DockPanel>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded"
Value="true">
<Trigger.EnterActions>
<BeginStoryboard Storyboard="{StaticResource strbExpand}" />
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard Storyboard="{StaticResource strbCollapse}" />
</Trigger.ExitActions>
</Trigger>
<Trigger Property="ExpandDirection"
Value="Down">
<Setter TargetName="ExpandSite"
Property="DockPanel.Dock"
Value="Bottom" />
<Setter TargetName="HeaderSite"
Property="DockPanel.Dock"
Value="Top" />
<Setter TargetName="HeaderSite"
Property="Style"
Value="{StaticResource ExpanderDownHeaderStyle}" />
</Trigger>
<!--
<Trigger Property="ExpandDirection" Value="Right">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderRightHeaderStyle}" />
</Trigger>
<Trigger Property="ExpandDirection" Value="Up">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderUpHeaderStyle}" />
</Trigger>
<Trigger Property="ExpandDirection" Value="Left">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left" />
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right" />
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderLeftHeaderStyle}" />
</Trigger>
-->
<Trigger Property="IsEnabled"
Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
和转换器：
public class VariableHeightAnimationConverter : IMultiValueConverter {
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) {
return System.Convert.ToDouble(values[0]) * System.Convert.ToDouble(values[1]);
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) {
throw new Exception("Not implemented");
}
}