Silverlight FullScreen 全屏

<UserControl x:Class="FullScreen.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Border HorizontalAlignment="Left" VerticalAlignment="Top" Padding="10" BorderThickness="1" CornerRadius="4" Background="#7F000000">
            <StackPanel>
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="总CPU占用：" TextWrapping="Wrap" d:LayoutOverrides="Height" Foreground="White"></TextBlock>
                    <TextBlock x:Name="txtCPULoad" TextWrapping="Wrap" d:LayoutOverrides="Height" Foreground="White"></TextBlock>
                </StackPanel>
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="当前CPU占用：" TextWrapping="Wrap" d:LayoutOverrides="Height" Foreground="White"></TextBlock>
                    <TextBlock x:Name="txtSLCPULoad" TextWrapping="Wrap" d:LayoutOverrides="Height" Foreground="White"></TextBlock>
                </StackPanel>
            </StackPanel>
        </Border>
        <Button Content="正常" Height="47" HorizontalAlignment="Left" Margin="152,123,0,0" Name="btnFull" VerticalAlignment="Top" Width="68" Click="btnFull_Click" />
    </Grid>
</UserControl>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Threading;

namespace FullScreen
{
    public partial class MainPage : UserControl
    {

        Analytics myAnalytics;

        public MainPage()
        {
            InitializeComponent();
            Loaded += new RoutedEventHandler(MainPage_Loaded);
            Application.Current.Host.Content.FullScreenChanged += new EventHandler(Content_FullScreenChanged);
        }

        void MainPage_Loaded(object sender, RoutedEventArgs e)
        {
            myAnalytics = new Analytics();
            DispatcherTimer timer = new DispatcherTimer();
            timer.Interval = TimeSpan.FromSeconds(1);
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

        void timer_Tick(object sender, EventArgs e)
        {
            txtCPULoad.Text = myAnalytics.AverageProcessorLoad.ToString();
            txtSLCPULoad.Text = myAnalytics.AverageProcessLoad.ToString();
        }

        void Content_FullScreenChanged(object sender, EventArgs e)
        {
            var content = Application.Current.Host.Content;
            if (content.IsFullScreen)
            {
                btnFull.Background = new SolidColorBrush(Colors.Yellow);
                LayoutRoot.Background = new SolidColorBrush(Colors.Yellow);
            }
            else
            {
                btnFull.Background = new SolidColorBrush(Colors.Red);
                LayoutRoot.Background = new SolidColorBrush(Colors.Red);
            }
        }

        private void btnFull_Click(object sender, RoutedEventArgs e)
        {
            var content = Application.Current.Host.Content;
            if (!content.IsFullScreen)
            {
                content.IsFullScreen = !content.IsFullScreen;
                btnFull.Content = "还原";
            }
            else
            {
                content.IsFullScreen = !content.IsFullScreen;
                btnFull.Content = "全屏";
            }
        }
    }
}