我一直在尝试使用 MVVM Light 框架在一个简单的 Windows 应用商店应用程序中使用附加行为。由于我们不能像在 Windows Phone 中那样使用 System.Windows.Interactivity,因此我一直在使用Windows.UI.Interactivity和WinRtBehaviors库。它们运行良好,但问题是我无法在数据模板中声明附加行为。
我真正想要的是将命令附加到 GridView 中的任何项目,以便我可以将项目 ID 作为参数传递。由于该附加行为不起作用,我找到的唯一解决方案是使用 GridView 的“SelectionChanged”事件并将 SelectedItem 作为参数传递给 ViewModel 中的属性:
<GridView Grid.Row="1"
x:Name="itemGridView"
AutomationProperties.AutomationId="ItemsGridView"
AutomationProperties.Name="Items"
TabIndex="1"
Padding="116,136,116,46"
ItemsSource="{Binding GeoTopArtists.topartists.artist}"
SelectionMode="Single"
SelectedItem="{Binding SelectedArtist, Mode=TwoWay}"
IsSwipeEnabled="False"
IsItemClickEnabled="False">
<WinRtBehaviors:Interaction.Behaviors>
<Win8nl_Behavior:EventToCommandBehavior Event="SelectionChanged" Command="SelectArtistCommand" CommandParameter="{Binding SelectedArtist.mbid}"/>
</WinRtBehaviors:Interaction.Behaviors>
<GridView.ItemTemplate>
<DataTemplate>
<Grid HorizontalAlignment="Left" Width="250" Height="250">
<Border Background="{StaticResource ListViewItemPlaceholderBackgroundThemeBrush}">
<Image Source="{Binding image[4].text}" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>
</Border>
<StackPanel VerticalAlignment="Bottom" Background="{StaticResource ListViewItemOverlayBackgroundThemeBrush}">
<TextBlock Text="{Binding name}" Foreground="{StaticResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextStyle}" Height="60" Margin="15,0,15,0"/>
<TextBlock Text="{Binding url}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>
</StackPanel>
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
做这样的事情会非常好(不需要在 ViewModel 中有SelectedArtist属性)
<GridView Grid.Row="1"
x:Name="itemGridView"
AutomationProperties.AutomationId="ItemsGridView"
AutomationProperties.Name="Items"
TabIndex="1"
Padding="116,136,116,46"
ItemsSource="{Binding GeoTopArtists.topartists.artist}"
SelectionMode="None"
IsSwipeEnabled="False"
IsItemClickEnabled="False">
<GridView.ItemTemplate>
<DataTemplate>
<Grid HorizontalAlignment="Left" Width="250" Height="250">
<Border Background="{StaticResource ListViewItemPlaceholderBackgroundThemeBrush}">
<Image Source="{Binding image[4].text}" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>
</Border>
<StackPanel VerticalAlignment="Bottom" Background="{StaticResource ListViewItemOverlayBackgroundThemeBrush}">
<TextBlock Text="{Binding name}" Foreground="{StaticResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextStyle}" Height="60" Margin="15,0,15,0"/>
<TextBlock Text="{Binding url}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>
</StackPanel>
<WinRtBehaviors:Interaction.Behaviors>
<Win8nl_Behavior:EventToCommandBehavior Event="Tapped" Command="SelectArtistCommand" CommandParameter="{Binding Artist.mbid}"/>
</WinRtBehaviors:Interaction.Behaviors>
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>