UWP TabView OneWay x:Bind 不更新

Question

我有一个 TabView，它的 ItemTemplate 是这样的：

<controls:TabView.ItemTemplate>
    <DataTemplate x:DataType="data:Playlist">
        <local:HeaderedPlaylistControl
            IsPlaylist="True"
            Loaded="HeaderedPlaylistControl_Loaded"
            MusicCollection="{x:Bind Mode=OneWay}" />
    </DataTemplate>
</controls:TabView.ItemTemplate>

这是 HeaderedPlaylistControl 的一部分：

<local:PlaylistControl
    AllowReorder="False"
    AlternatingRowColor="True"
    ItemsSource="{x:Bind MusicCollection.Songs, Mode=OneWay}">
    <local:PlaylistControl.Header>
        <controls:ScrollHeader Mode="Sticky">
            <UserControl>
                <Grid
                    x:Name="PlaylistInfoGrid"
                    Padding="10"
                    Background="{ThemeResource SystemColorHighlightColor}">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Image
                        x:Name="PlaylistCover"
                        Grid.RowSpan="3"
                        Width="180"
                        Height="180"
                        Margin="20"
                        Source="Assets/monotone_bg_wide.png" />
                    <TextBlock
                        x:Name="PlaylistNameTextBlock"
                        Grid.Column="1"
                        Margin="0,5"
                        VerticalAlignment="Center"
                        FontSize="36"
                        Foreground="White"
                        Style="{StaticResource HeaderTextBlockStyle}"
                        Text="{x:Bind MusicCollection.Name, Mode=OneWay}" />
                    <TextBlock
                        x:Name="PlaylistInfoTextBlock"
                        Grid.Row="1"
                        Grid.Column="1"
                        Margin="0,5"
                        VerticalAlignment="Top"
                        Foreground="White"
                        Text="{x:Bind MusicCollection.Songs, Converter={StaticResource SongCountConverter}, Mode=OneWay}" />
                </Grid>
            </UserControl>
        </controls:ScrollHeader>
    </local:PlaylistControl.Header>
</local:PlaylistControl>

当我在选项卡之间切换时，HeaderedPlaylistControl 不会更新其内容。这是为什么？

是不是因为MusicCollection 属性（属于Playlist类型）切换标签页时没有通知绑定？如果是这样，我应该把通知放在哪里？ Playlist的定义是here.

HeaderedPlaylistControl 是 here:

Answer 1

是的，正如您所怀疑的，问题是 MusicCollection 属性是一个普通的属性，它不会通知更改。要使您的代码正常工作，您需要使 MusicCollection 属性成为依赖项属性（请参阅 docs）。这是一种最适合可视化控件的数据绑定属性的属性，并且还有许多附加功能。

public static readonly DependencyProperty MusicCollectionProperty =
    DependencyProperty.Register(
        nameof(MusicCollection), typeof(Playlist),
        typeof(HeaderedPlaylistControl), null
    );

public Playlist MusicCollection
{
    get { return (bool)GetValue(MusicCollectionProperty); }
    set { SetValue(MusicCollectionProperty, value); }
}

UWP TabView OneWay x:Bind 不更新

UWP TabView OneWay x:Bind does not update

c#

xaml

win-universal-app

uwp