c# - ListViewItem IsSelected Binding - 适用于 WPF，但不适用于 WinRT

Question

我正在尝试将 ListViewItem 的 IsSelected 属性绑定(bind)到 ViewModel 中的属性。它在 WPF 中运行良好，但在 Windows RT 中 IsSelected 属性永远不会被设置。

public class Item : INotifyPropertyChanged
{
    private readonly string name;
    private bool isSelected;
    public event PropertyChangedEventHandler PropertyChanged;

    public bool IsSelected
    {
        get { return isSelected; }
        set { isSelected = value; RaisePropertyChanged("IsSelected"); }
    }

    public string Name { get { return name; } }

    public Item(string name)
    {
        this.name = name;
    }

    protected void RaisePropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class ViewModel
{
    private readonly ObservableCollection<Item> items = new ObservableCollection<Item>(Enumerable.Range(0, 10).Select(p => new Item(p.ToString())));
    public ObservableCollection<Item> Items { get { return items; } }
}

public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();
        DataContext = new ViewModel();
    }
}

xaml:

<StackPanel Orientation="Horizontal">
    <ListView ItemsSource="{Binding Path=Items}" SelectionMode="Multiple">
        <ListView.ItemContainerStyle>
            <Style TargetType="ListViewItem">
                <Setter Property="IsSelected" Value="{Binding Path=IsSelected, Mode=TwoWay}"/>
            </Style>
        </ListView.ItemContainerStyle>
    </ListView>
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Path=Name}"/>
         </DataTemplate>
     </ListView.ItemTemplate>
</StackPanel>

我可以单击屏幕上的项目，但 IsSelected 属性未传播到 ViewModel。有什么想法吗？

Answer 1

做到这一点的一个好而简单的方法是子类化 ListView

public class MyListView : ListView
    {
        protected override void PrepareContainerForItemOverride(Windows.UI.Xaml.DependencyObject element, object item)
        {
            base.PrepareContainerForItemOverride(element, item);
            // ...
            ListViewItem listItem = element as ListViewItem;
            Binding binding = new Binding();
            binding.Mode = BindingMode.TwoWay;
            binding.Source = item;
            binding.Path = new PropertyPath("Selected");
            listItem.SetBinding(ListViewItem.IsSelectedProperty, binding);
        }
    }

或者，看来你也可以用 WinRT XAML Toolkit 来做.

<ListView
            x:Name="lv"
            Grid.Row="1"
            Grid.Column="1"
            SelectionMode="Multiple"
            HorizontalAlignment="Left"
            Width="500">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <TextBlock
                        Extensions:ListViewItemExtensions.IsSelected="{Binding IsSelected}"
                        Extensions:ListViewItemExtensions.IsEnabled="{Binding IsEnabled}"
                        Text="{Binding Text}"
                        Margin="15,5"
                        FontSize="36" />
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

就我个人而言，我使用第一种方法，因为它更灵活，而且我需要绑定(bind)一些自动化属性。

感谢 ForInfo 和 ehuna: http://social.msdn.microsoft.com/Forums/windowsapps/en-US/9a0adf35-fdad-4419-9a34-a9dac052a2e3/listviewitemisselected-data-binding-in-style-setter-is-not-working