c# - 在 WPF 中打开 ContextMenu 时保留 DataGrid IsSelectionActive？

Question

我有一个 DataGrid，它的样式为 IsSelectionActive；然而，一旦 ContextMenu 打开，网格就会丢失 IsSelectionActive 并且在用户看来好像是上下文菜单以某种方式进行了选择并且可能会使用户感到困惑。

有没有办法在上下文菜单打开时保留 IsSelectionActive？

<ControlTemplate.Triggers>
    <MultiTrigger>
        <MultiTrigger.Conditions>
            <!--<Condition Property="Selector.IsFocused" Value="True" />-->
            <Condition Property="IsSelected" Value="True" />
        </MultiTrigger.Conditions>

        <Setter Property="Background" Value="Red" />
    </MultiTrigger>

    <MultiTrigger>
        <MultiTrigger.Conditions>
            <Condition Property="Selector.IsFocused" Value="False" />
            <Condition Property="IsSelected" Value="False" />
        </MultiTrigger.Conditions>

        <Setter Property="Background" Value="Green" />
    </MultiTrigger>

    <MultiTrigger>
        <MultiTrigger.Conditions>
            <Condition Property="Selector.IsFocused" Value="False" />
            <Condition Property="IsSelected" Value="True" />
        </MultiTrigger.Conditions>

        <Setter Property="Background" Value="Blue" />
    </MultiTrigger>

Answer 1

这是我在测试应用程序中用于获得所需行为的完整 XAML:

<Window x:Class="DataGridSelectionActive.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:DataGridSelectionActive"
        Title="MainWindow" Height="350" Width="525">

    <!-- People is just an ObservableCollection derived class. -->
    <Window.DataContext>
        <local:People/>
    </Window.DataContext>

    <Window.Resources>

        <ContextMenu x:Key="dataGridContextMenu">
            <MenuItem Header="Some context menu item"/>
        </ContextMenu>

        <Style TargetType="{x:Type DataGridCell}">
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/>
                    <Setter Property="BorderBrush" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
                </Trigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="True"/>
                        <Condition Binding="{Binding IsKeyboardFocusWithin, RelativeSource={RelativeSource AncestorType=DataGrid}}" Value="False"/>
                    </MultiDataTrigger.Conditions>
                    <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
                    <Setter Property="BorderBrush" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding IsSelected, RelativeSource={RelativeSource Self}}" Value="True"/>
                        <Condition Binding="{Binding ContextMenu.IsOpen, RelativeSource={RelativeSource AncestorType=DataGrid}}" Value="True"/>
                    </MultiDataTrigger.Conditions>
                    <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/>
                    <Setter Property="BorderBrush" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>

    </Window.Resources>

    <DockPanel>
        <!-- Added button for testing keyboard focus. -->
        <Button DockPanel.Dock="Top" Content="Click me"/>
        <DataGrid ItemsSource="{Binding}" ContextMenu="{StaticResource dataGridContextMenu}"/>
    </DockPanel>

</Window>

启用此行为的关键是，如果具有冲突 Setter 的多个触发器同时处于事件状态，则最后一个获胜。