CODEWITHSUNDEEP
c#xamlwindows-runtimewinrt-xaml
David Klimek
David Klimek

Reputation: 205

ListViewItem IsSelected Binding - Works for WPF, but not for WinRT

I'm trying to bind the IsSelected property of a ListViewItem to a property in a ViewModel. It works fine in WPF, but in Windows RT the IsSelected property is never getting set. 

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>

I'm able to click on the items on the screen, but the IsSelected property isn't propagating to the ViewModel. Any ideas why?

Upvotes: 10

Views: 6706

Answers (2)

Filip Skakun
Filip Skakun

Reputation: 31724

WinRT doesn't support bindings in setters at all as of Windows 8.0. Bing for workarounds.

Upvotes: 3

dcastro
dcastro

Reputation: 68640

A good and easy way to do this is to subclass 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);
        }
    }

Alternatively, it seems you can also do it with WinRT XAML Toolkit.

<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>

Personally, I used the first approach because it's more flexible and I needed to bind a few Automation Properties.

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

Upvotes: 4

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