WPF自定义圆角按钮嵌入ElementHost后偶尔无响应问题

开发PowerPoint插件时，UI通过WinForm的ElementHost控件嵌入WPF实现。自定义圆角按钮外观显示正常，但偶尔出现鼠标移入无响应的情况：hover/press事件不触发，点击时会选中后方的父元素，如同按钮处于“幽灵状态”。移除模板中实现圆角的Border后问题消失，默认按钮无此问题；但自定义按钮获得焦点时功能完全正常，推测可能与性能相关。

承载按钮的UserControl内Grid代码 #

<Viewbox Grid.Column="2" Grid.RowSpan="3" HorizontalAlignment="Right" Margin="0,5,10,5">
   <Grid Height="100" Width="100">
      <Grid.RowDefinitions>
         <RowDefinition/>
         <RowDefinition/>
         <RowDefinition/>
      </Grid.RowDefinitions>
      <Grid.ColumnDefinitions>
         <ColumnDefinition/>
         <ColumnDefinition/>
         <ColumnDefinition/>
      </Grid.ColumnDefinitions>
      
      <Button Grid.Row="0" Grid.Column="0"  Background="red" Style="{StaticResource AnchorPoint}" Click="Button_Click_1"/>
      <!--<Button Grid.Row="0" Grid.Column="1" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="0" Grid.Column="2" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="1" Grid.Column="2" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="1" Grid.Column="1" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="1" Grid.Column="0" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="2" Grid.Column="0" Style="{StaticResource AnchorPoint}"/>
      <Button Grid.Row="2" Grid.Column="1" Style="{StaticResource AnchorPoint}"/>-->
      <Button Grid.Row="2" Grid.Column="2" Style="{StaticResource AnchorPoint}"/>
      <Button Content="Button" Grid.Column="2" Grid.Row="1"/>
   </Grid>
</Viewbox>

按钮样式代码 #

<Style TargetType="Button" x:Key="AnchorPoint">
   <Setter Property="Background" Value="Transparent"></Setter>
   <Setter Property="Foreground" Value="Transparent"></Setter>
   <Setter Property="BorderBrush" Value="{x:Null}"></Setter>
   <Setter Property="BorderThickness" Value="0"></Setter>
   <Setter Property="HorizontalAlignment" Value="Stretch"></Setter>
   <Setter Property="VerticalAlignment" Value="Stretch"></Setter>
   <Setter Property="Margin" Value="0,0,0,0"></Setter>

   <Setter Property="Template">
      <Setter.Value>
         <ControlTemplate TargetType="Button">

            <Border x:Name="border" CornerRadius="2" Margin="0" BorderThickness="2" Style="{StaticResource TestHidden}">
            <ContentPresenter VerticalAlignment="Center" HorizontalAlignment="Center" ContentSource="Content"/>
            </Border>

            <ControlTemplate.Triggers>
               <Trigger Property="IsPressed" Value="True">
                  <Setter Property="Background" Value="Red" TargetName="border"></Setter>
               </Trigger>

               <Trigger Property="IsFocused" Value="True">
                  <Setter Property="Background" Value="blue" TargetName="border"></Setter>
               </Trigger>

               <Trigger Property="IsMouseOver" Value="True">
                  <Setter Property="Background" Value="green" TargetName="border"></Setter>
               </Trigger>
            </ControlTemplate.Triggers>

         </ControlTemplate>
      </Setter.Value>
   </Setter>
</Style>

Border样式代码 #

<Style x:Key="TestHidden" TargetType="Border">
   <Setter Property="BorderBrush" Value="{StaticResource SkyGrey}"/>
   <Setter Property="Background" Value="{x:Null}" />
   <Setter Property="Focusable" Value="False"></Setter>
   <Style.Triggers>
      <Trigger Property="IsMouseOver" Value="True">
         <Setter Property="BorderBrush" Value="{StaticResource SkyGrey}" />
         <Setter Property="Background" Value="{StaticResource SkyGreyHover}" />
      </Trigger>
   </Style.Triggers>
</Style>

内容的提问来源于stack exchange，提问作者ImCattastic