Windows Phone 8 Panorama SelectionIndex在浏览项目时不会改变

Question

我创建了全景控件，并从ItemSource绑定了ItemSource。现在，当我通过滑动来改变所选的全景项目时，所选的索引总是设置为-1。我不知道我在执行过程中做错了什么。两个选择更改事件都不会被解雇。代码：

<phone:Panorama Grid.Row="1"  Visibility="Visible"
       x:Name="PnrVwMainNews"
       ItemsSource="{Binding ParnormaItemsData}"
       ItemContainerStyle="{StaticResource PanoramaContainerItemStyle}">
    <phone:Panorama.ItemTemplate>
        <DataTemplate>
            <!-- Panorma Items Template -->
            <Controls:DynamicContentControl Content="{Binding UsrCntrlDynamic}" />
        </DataTemplate>
    </phone:Panorama.ItemTemplate>
</phone:Panorama> 

PanoramaContainerItemStyle

<Style x:Key="PanoramaContainerItemStyle" TargetType="phone:PanoramaItem">
        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
        <Setter Property="VerticalContentAlignment" Value="Stretch" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="phone:PanoramaItem">
                    <Grid Background="{TemplateBinding Background}" Margin="12,0,0,0">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="auto" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>

                        <ContentPresenter Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Grid.Row="1" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

Answer 1

我在这里看不到任何Selection_Changed事件的实现/钩住。

SelectionChanged="Panorama_SelectionChanged"

您应该首先在全景级别上定义此事件。(不在PanoramaContainerItemStyle内)

Answer 2

最后在SelectedItem事件处理程序中将null赋值给SelectionChanged，这样每次都会选择新的项。