wpf - 当应用程序失去焦点/替代 IsKeyboardFocusWithin 时，最后一个焦点项目的视觉指示

Question

在具有多个要与之交互的面板或文档的应用程序中，需要清楚地指示应用程序的哪个区域具有焦点。Visual Studio 本身就是一个很好的例子。

下面的MCV 示例接近达到预期的效果。
但是，因为它使用IsKeyboardFocusWithin，所以当应用程序本身失去焦点时，不会维护应用程序中最近获得焦点的项目。

期望行为：当应用程序失去焦点时，保持由蓝色“SelectedColor”指示的焦点项。Visual Studio 执行此操作。

当应用失去焦点时，如何保持焦点指示？

• 代码

  注意：没有代码隐藏。这是完整的例子。

  <Window x:Class="TrackFocusMCVE.MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"   
      Title="MainWindow" Height="150" Width="300">
  <Window.Resources>
  
      <SolidColorBrush x:Key="MouseOverColor" Color="#FF1C97EA"/>
      <SolidColorBrush x:Key="SelectedColor" Color="#FF007ACC"/>
      <SolidColorBrush x:Key="InactiveColor" Color="#19FFFFFF"/>
      <SolidColorBrush x:Key="BackgroundColor" Color="#FF44454B"/>
  
      <Style x:Key="TabControlStyle" TargetType="{x:Type TabControl}">
          <Setter Property="Margin" Value="5,15,5,7"/>
          <Setter Property="Padding" Value="0"/>
          <Setter Property="BorderThickness" Value="0,2,0,0"/>
          <Setter Property="BorderBrush" Value="{DynamicResource InactiveColor}"/>
          <Setter Property="Foreground" Value="White"/>
          <Setter Property="Background" Value="{StaticResource BackgroundColor}"/>
          <Setter Property="HorizontalContentAlignment" Value="Center"/>
          <Style.Triggers>
              <Trigger Property="IsKeyboardFocusWithin" Value="True">
                  <Setter Property="TabControl.BorderBrush" Value="{StaticResource SelectedColor}"/>
              </Trigger>
          </Style.Triggers>
      </Style>
  
      <Style x:Key="TabItemStyle" TargetType="{x:Type TabItem}">
          <Setter Property="Padding" Value="15,2"/>
          <Setter Property="Foreground" Value="White"/>
          <Setter Property="Background" Value="Transparent"/>
          <Setter Property="HorizontalContentAlignment" Value="Center"/>
          <Setter Property="Template">
              <Setter.Value>
                  <ControlTemplate TargetType="{x:Type TabItem}">
                      <Border Name="TabBorder" MinWidth="40" MinHeight="20"
                              BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}"
                              Margin="{TemplateBinding Margin}" Padding="{TemplateBinding Padding}"
                              Background="{TemplateBinding Background}">
                          <ContentPresenter ContentSource="Header" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                      </Border>
                      <ControlTemplate.Triggers>
                          <MultiDataTrigger>
                              <MultiDataTrigger.Conditions>
                                  <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="true" />
                                  <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="false"/>
                              </MultiDataTrigger.Conditions>
                              <Setter TargetName="TabBorder" Property="Background" Value="{StaticResource MouseOverColor}"/>
                          </MultiDataTrigger>
                          <MultiDataTrigger>
                              <MultiDataTrigger.Conditions>
                                  <Condition Binding="{Binding IsKeyboardFocusWithin, RelativeSource={RelativeSource Self}}" Value="false" />
                                  <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="true"/>
                              </MultiDataTrigger.Conditions>
                              <Setter TargetName="TabBorder" Property="Background" Value="{StaticResource InactiveColor}"/>
                          </MultiDataTrigger>
                          <MultiDataTrigger>
                              <MultiDataTrigger.Conditions>
                                  <Condition Binding="{Binding IsKeyboardFocusWithin, RelativeSource={RelativeSource Self}}" Value="true" />
                                  <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="true"/>
                              </MultiDataTrigger.Conditions>
                              <Setter TargetName="TabBorder" Property="Background" Value="{StaticResource SelectedColor}"/>
                          </MultiDataTrigger>
                      </ControlTemplate.Triggers>
                  </ControlTemplate>
              </Setter.Value>
          </Setter>
      </Style>
  </Window.Resources>
      <Grid Background="DimGray">
          <Grid.ColumnDefinitions>
              <ColumnDefinition/>
              <ColumnDefinition/>
          </Grid.ColumnDefinitions>
          <TabControl Grid.Column="0" x:Name="tc1" Style="{DynamicResource TabControlStyle}">
              <TabItem Header="1" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
              <TabItem Header="2" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
              <TabItem Header="3" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
          </TabControl>
          <TabControl Grid.Column="1" x:Name="tc2" Style="{DynamicResource TabControlStyle}">
              <TabItem Header="4" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
              <TabItem Header="5" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
              <TabItem Header="6" Content="Tab Content" Style="{DynamicResource TabItemStyle}"/>
          </TabControl>
      </Grid>
  </Window>
  

标签： wpfuser-interfacemvvmfocusdatatrigger

Answer 1

部分答案：

当窗口失去焦点时，您可以通过将 MultiDataTrigger 条件更改为使用 IsFocused 而不是 IsKeyboardFocusWithin 来使焦点选项卡保持蓝色，如下所示：

<MultiDataTrigger>
    <MultiDataTrigger.Conditions>
        <Condition Binding="{Binding IsFocused, RelativeSource={RelativeSource Self}}" Value="true" />
        <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="true" />
    </MultiDataTrigger.Conditions>
    <Setter TargetName="TabBorder" Property="Background" Value="{StaticResource SelectedColor}" />
</MultiDataTrigger>

但是，没有直接的方法可以知道 TabControl 的子项何时聚焦，以便您可以将边框变为蓝色。