.net – 如何保持DataGridRow焦点和选择同步？

这是一些示例代码.特别注意DataGridAttachment类.这就是定义附加属性的位置,以及逻辑在哪里对焦点和选择更改事件作??出反应.

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);
        }
    }
}