.net - 如何保持 DataGridRow 焦点和选择同步？

Question

我有一个 DataGrid并且我希望选定行和焦点行同步，即如果焦点行发生变化，则选定行发生变化，如果选定行发生变化，则它成为焦点行。

给定具有以下 XAML 的 WPF 窗口，如何同步焦点行和选定行？

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">

    <Grid>
        <Grid.Resources>

            <x:Array x:Key="MyList" Type="sys:String" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:sys="clr-namespace:System;assembly=mscorlib">
                <sys:String>Hello</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
                <sys:String>World</sys:String>
            </x:Array>

            <Style TargetType="{x:Type DataGrid}">
                <Setter Property="AlternationCount" Value="2" />
                <Setter Property="AutoGenerateColumns" Value="False"/>
            </Style>

            <Style TargetType="{x:Type DataGridCell}">
                <Setter Property="Background" Value="Transparent"/>
                <Setter Property="Focusable" Value="False"/>
            </Style>

            <Style TargetType="{x:Type DataGridRow}">
                <Setter Property="Focusable" Value="True"/>
                <Style.Triggers>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="AlternationIndex" Value="0"/>
                            <Condition Property="IsSelected" Value="False"/>
                        </MultiTrigger.Conditions>
                        <Setter Property="Background" Value="White"/>
                    </MultiTrigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="AlternationIndex" Value="1"/>
                            <Condition Property="IsSelected" Value="False"/>
                        </MultiTrigger.Conditions>
                        <Setter Property="Background" Value="Gainsboro"/>
                    </MultiTrigger>
                    <Trigger Property="AlternationIndex" Value="1">
                        <Setter Property="Background" Value="Gainsboro"/>
                    </Trigger>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter Property="Background" Value="#BF228B22"/>
                        <Setter Property="BorderBrush" Value="ForestGreen"/>
                        <Setter Property="BorderThickness" Value="1"/>
                    </Trigger>
                </Style.Triggers>
            </Style>

        </Grid.Resources>

        <DataGrid ItemsSource="{StaticResource MyList}">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding}" Width="*"/>
            </DataGrid.Columns>
        </DataGrid>

    </Grid>

</Window>

通过下图，您可以看到红色的焦点矩形和绿色的选定行显然不同步，因为我认为这是默认行为。我想要的是它们始终是同一个，即 SelectedRow 始终是 Focused，FocusedRow 始终是 Selected。

Answer 1

尝试使用附加属性来监听 DataGrid 内的焦点更改和选择更改事件。当其中任何一种情况发生时，您都可以通过更改选择或焦点来相应地使用react。

这是一些示例代码。请特别注意 DataGridAttachment 类。这是定义附加属性的地方，也是逻辑对焦点和选择更改事件使用react的地方。

MainWindow.xaml

<Window x:Class="_15098869.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:_15098869"
    Title="MainWindow"
    Width="525"
    Height="350">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>
    <DataGrid Name="DataGrid"
              ItemsSource="{Binding Path=Items}"
              local:DataGridAttachment.SyncSelectionWithFocus="True" />
    <Button Grid.Row="1"
            Click="MoveSelectionButtonOnClick"
            Content="Move Selection" />
</Grid>

MainWindow.xaml.cs(代码隐藏)

using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;

namespace _15098869
{
    /// <summary>
    ///     Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow
    {
        public MainWindow()
        {
            InitializeComponent();

            DataContext = this;

            Items = new ObservableCollection<DemoItem>();
            Items.Add(new DemoItem {FirstName = "John", LastName = "Doe"});
            Items.Add(new DemoItem {FirstName = "Jane", LastName = "Doe"});
            Items.Add(new DemoItem {FirstName = "Bob", LastName = "Doe"});
        }

        public ObservableCollection<DemoItem> Items { get; private set; }

        public void MoveSelectionButtonOnClick(object sender, RoutedEventArgs e)
        {
            var max = DataGrid.Items.Count - 1;
            DataGrid.SelectedIndex = DataGrid.SelectedIndex == max ? 0 : DataGrid.SelectedIndex + 1;
        }
    }

    public class DemoItem
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }

    public static class DataGridAttachment
    {
        public static readonly DependencyProperty SyncSelectionWithFocusProperty =
            DependencyProperty.RegisterAttached("SyncSelectionWithFocus", typeof (bool), typeof (DataGridAttachment), new PropertyMetadata(default(bool), SyncSelectionWithFocusChanged));

        private static void SyncSelectionWithFocusChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            var dataGrid = dependencyObject as DataGrid;
            if (dataGrid == null) return;

            var shouldSync = GetSyncSelectionWithFocus(dataGrid);

            if (shouldSync)
            {
                dataGrid.AddHandler(UIElement.GotFocusEvent, new RoutedEventHandler(DataGridOnGotFocus));
                dataGrid.AddHandler(Selector.SelectionChangedEvent, new SelectionChangedEventHandler(DataGridOnSelectionChanged));
            }
        }

        private static void DataGridOnGotFocus(object sender, RoutedEventArgs e)
        {
            var dataGrid = sender as DataGrid;
            var element = e.OriginalSource as DataGridCell;

            if (dataGrid == null || element == null) return;
            dataGrid.SelectedItem = element.DataContext;
        }

        private static void DataGridOnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            var dataGrid = sender as DataGrid;

            if (dataGrid == null) return;

            if (!dataGrid.IsKeyboardFocusWithin)
            {
                dataGrid.Focus();
            }
        }

        public static void SetSyncSelectionWithFocus(DataGrid element, bool value)
        {
            element.SetValue(SyncSelectionWithFocusProperty, value);
        }

        public static bool GetSyncSelectionWithFocus(DataGrid element)
        {
            return (bool) element.GetValue(SyncSelectionWithFocusProperty);
        }
    }
}