自定义 CollectionViewType 不支持使用 shift 键进行多选

Question

在 Window 中，我使用带有 CollectionViewSource 的自定义 CollectionViewType 将 ListBox 中的项目分组（EmployeeCollectionView）。

MainWindow.xaml:

<Window x:Class="ListBoxSelectionMode.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:ListBoxSelectionMode">
<Window.Resources>
    <CollectionViewSource x:Key="EmployeesSource" Source="{Binding Employees}" CollectionViewType="local:EmployeeCollectionView" />

    <DataTemplate x:Key="EmployeeTemplate">
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="{Binding FirstName}" />
            <TextBlock Text="{Binding LastName}" />
        </StackPanel>
    </DataTemplate>
</Window.Resources>

<ListBox ItemsSource="{Binding Source={StaticResource EmployeesSource}}"
         ItemTemplate="{StaticResource EmployeeTemplate}"
         SelectionMode="Extended">
    <ListBox.GroupStyle>
        <x:Static Member="GroupStyle.Default"/>
    </ListBox.GroupStyle>
</ListBox>

MainWindow.xaml.cs：

public partial class MainWindow : Window
{
    public IEnumerable<Employee> Employees { get; set; }

    public MainWindow()
    {
        InitializeComponent();

        Employees = new List<Employee>
        {
            new Employee { FirstName = "FirstName1", LastName = "LastName1", HireDate = new DateTime(1970, 1, 1) },
            new Employee { FirstName = "FirstName2", LastName = "LastName2", HireDate = new DateTime(1970, 1, 1) },
            new Employee { FirstName = "FirstName3", LastName = "LastName3", HireDate = new DateTime(1980, 1, 1) },
            new Employee { FirstName = "FirstName4", LastName = "LastName4", HireDate = new DateTime(1980, 1, 1) },
            new Employee { FirstName = "FirstName5", LastName = "LastName5", HireDate = new DateTime(1990, 1, 1) },
            new Employee { FirstName = "FirstName6", LastName = "LastName6", HireDate = new DateTime(1990, 1, 1) }
        };

        DataContext = this;
    }
}

EmployeeCollectionView.cs：

class EmployeeCollectionView : ListCollectionView
{
    private readonly IList<EmployeeCollectionViewGroup> _groups;
    public override ReadOnlyObservableCollection<object> Groups
    {
        get { return new ReadOnlyObservableCollection<object>(new ObservableCollection<object>(_groups)); }
    }

    public EmployeeCollectionView(IList list)
        : base(list)
    {
        _groups = list
             .OfType<Employee>()
            .GroupBy(x => x.HireDate)
            .Select(x => new EmployeeCollectionViewGroup(x.Key, x))
            .ToList();
    }
}

EmployeeCollectionViewGroup.cs：

class EmployeeCollectionViewGroup : CollectionViewGroup
{
    public EmployeeCollectionViewGroup(object name, IEnumerable<object> protectedItems)
        : base(name)
    {
        foreach (var protectedItem in protectedItems)
            ProtectedItems.Add(protectedItem);
    }

    public override bool IsBottomLevel
    {
        get { return true; }
    }
}

问题：为什么我不能使用 SHIFT 键选择多个项目？

编辑：使用 CTRLworks 进行多选。

Answer 1

您是否尝试按下 CTRL 键而不是 SHIFT 键？在您的 List 声明之后还要移动 InitializeComponent。