我在(伪)启动页上使用 Silverlight 工具包中的 PerformanceProgressBar。但是,它只显示一个移动点。怎么了?
<Grid x:Name="LayoutRoot" Background="White">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <Grid x:Name="ActiveSplash" Height="Auto" Width="480" Background="Pink" Grid.Row="1" Visibility="Visible">            
        <Image Name="SplashScreenImage" Source="/SplashScreenImage.jpg"></Image>
        <toolkit:PerformanceProgressBar Width="480" Height="Auto"                                            
                    IsIndeterminate="True" 
                    Foreground="Blue" 
                    Background="Blue"
                    Margin="0,104,0,0" />
    </Grid>
    <Grid x:Name="ContentPanel" Visibility="Collapsed" Grid.Row="2">
        <!-- stuff -->
    </Grid>
</Grid>