Silverlight：为什么此绑定表达式不起作用？

Question

I'm having difficulty with a binding expression in Silverlight 3 for the Windows Phone 7.

<Grid x:Name="LayoutRoot" Background="Transparent">    
    <controls:Pivot ItemsSource="{Binding SectionViewModels}">
    <!-- ... -->
    <controls:Pivot.ItemTemplate>
        <DataTemplate>
            <Grid>
                <!-- this is the troublesome binding (for Visibility) -->
                <TextBlock Style="{StaticResource disabledText}" 
                           Visibility="{Binding ElementName=LayoutRoot, Path=DataContext.NoStoryContent}">
                    Do you have a network connection?
                </TextBlock>
                <!-- ... -->

The style, in app.xaml :

<Style x:Key="disabledText" TargetType="TextBlock">
    <Setter Property="Foreground" Value="{StaticResource PhoneDisabledBrush}" />
    <Setter Property="TextWrapping" Value="Wrap" />
    <Setter Property="FontSize" Value="{StaticResource PhoneFontSizeLarge}" />
</Style>

Code behind:

public Visibility NoStoryContent
{
    get
    {
        // trivial return value for debugging
        // no breakpoint here is hit
        return Visibility.Collapsed;
    }
}

public Sections()
{
    InitializeComponent();
    LayoutRoot.DataContext = this;
}

What am I doing wrong here? I suspect I have a mistake in the binding expression, but I'm not sure where.

Update : I don't see any error messages in the debug output.

Update 2 : When I say 'doesn't work', I mean 'the control is always visible even though I'm trying to make it be collapsed, and the property that its Visibility is binding to is never accessed.'

Answer 1

试试{Binding NoStoryContent}

Answer 2

您应该在您的课程中实现iNotifyPropertyChanged