我是WPF的新手，我又需要帮助......
我有一个带圆角的扩展器，但我不喜欢这个，我想要矩形角。谁能告诉我如何解决这个问题呢？ 这是我的扩展器 ..风格：
<Style x:Key="exp_AInfo_Style" TargetType="Expander">
<Setter Property="IsExpanded" Value="True"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="VerticalAlignment" Value="Top"/>
<Setter Property="Margin" Value="18,5,0,0"/>
<Setter Property="Width" Value="259"/>
<Setter Property="Height" Value="29"/>
<Setter Property="FontSize" Value="14"/>
<Style.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter Property="Height" Value="155"/>
</Trigger>
</Style.Triggers>
</Style>
和对象：
<Expander x:Name="exp_AInfo" Header="Allgemeine Info's"
Style="{StaticResource exp_AInfo_Style}" Height="116"
>
<Expander.Background>
<ImageBrush ImageSource="pct/expander.png" Opacity="0.9"/>
</Expander.Background>
<Grid Height="112">
<!--many many objects-->
</Grid>
</Expander>
感谢4位帮助
答案 0 :(得分：0)
所有关于ToggleButton ControlTemplate的CornerRadius。
你去了：
<ControlTemplate x:Key="ExpanderToggleButton"
TargetType="{x:Type ToggleButton}">
<Border x:Name="Border"
CornerRadius="0,0,0,0"
BorderThickness="1" Background="White" BorderBrush="Black">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="MouseOver">
</VisualState>
<VisualState x:Name="Pressed">
</VisualState>
<VisualState x:Name="Disabled">
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="CheckStates">
<VisualState x:Name="Checked">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
Storyboard.TargetName="CollapsedArrow">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{x:Static Visibility.Hidden}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
Storyboard.TargetName="ExpandededArrow">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{x:Static Visibility.Visible}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Unchecked" />
<VisualState x:Name="Indeterminate" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid>
<Path x:Name="CollapsedArrow"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Data="M 0 0 L 4 4 L 8 0 Z">
<Path.Fill>
<SolidColorBrush Color="Black" />
</Path.Fill>
</Path>
<Path x:Name="ExpandededArrow"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Visibility="Collapsed"
Data="M 0 4 L 4 0 L 8 4 Z">
<Path.Fill>
<SolidColorBrush Color="Black" />
</Path.Fill>
</Path>
</Grid>
</Border>
</ControlTemplate>
<Style TargetType="{x:Type Expander}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Expander}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition x:Name="ContentRow"
Height="0" />
</Grid.RowDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="MouseOver" />
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border"
Grid.Row="0"
BorderThickness="1"
CornerRadius="2,2,0,0">
<Border.BorderBrush>
<LinearGradientBrush EndPoint="0,1"
StartPoint="0,0">
<GradientStop Color="White" Offset="0" />
<GradientStop Color="White" Offset="1" />
</LinearGradientBrush>
</Border.BorderBrush>
<Border.Background>
<LinearGradientBrush StartPoint="0,0"
EndPoint="0,1">
<LinearGradientBrush.GradientStops>
<GradientStopCollection>
<GradientStop Color="White" Offset="0.0" />
<GradientStop Color="White" Offset="1.0" />
</GradientStopCollection>
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
</Border.Background>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<ToggleButton OverridesDefaultStyle="True"
Template="{StaticResource ExpanderToggleButton}"
IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
<ToggleButton.Background>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="White" Offset="0" />
<GradientStop Color="White" Offset="1" />
</LinearGradientBrush>
</ToggleButton.Background>
</ToggleButton>
<ContentPresenter Grid.Column="1"
Margin="4"
ContentSource="Header"
RecognizesAccessKey="True" />
</Grid>
</Border>
<Border x:Name="Content"
Grid.Row="1"
BorderThickness="1,0,1,1"
CornerRadius="0,0,0,0">
<ContentPresenter Margin="4" />
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter TargetName="ContentRow"
Property="Height"
Value="{Binding DesiredHeight, ElementName=Content}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>