Silverlight for Windows Phone 7Popup

　　在Windows Phone 7开发者我在不使用Progressbar的前提下又想告诉用户程序正在运行，显示一个进度对话框，这时我们就可以用Popup。

前台

 <Popup x:Name="ProgressPopup" Width="300" IsOpen="False" HorizontalAlignment="Center"
                   VerticalAlignment="Top" d:LayoutOverrides="Width, HorizontalMargin" Margin="89,203,91,0">
                <Border BorderThickness="10" BorderBrush="Black" Background="DarkGray" Padding="30,30">
                    <StackPanel>
                        <TextBlock MaxHeight="100" Foreground="White"  FontWeight="Bold"  FontSize="36" x:Name="txt" Text="1">
                            <TextBlock.Triggers>
                                <EventTrigger RoutedEvent="TextBlock.Loaded">
                                    <BeginStoryboard> <Storyboard>
                                        <DoubleAnimation   AutoReverse="True" Duration="0:0:1"
                                     From="1.0" RepeatBehavior="Forever"  Storyboard.TargetName="txt" Storyboard.TargetProperty="Opacity"   To="0.0"/> 
                                    </Storyboard>
                                    </BeginStoryboard>                            
                                </EventTrigger>                       
                            </TextBlock.Triggers>
                        </TextBlock>
                    </StackPanel>
                </Border>
            </Popup>

后台

 public partial class MainPage : PhoneApplicationPage
    {
        Storyboard _timer = new Storyboard();
      
        int i=0;
        public MainPage()
        {
            InitializeComponent();

            _timer.Duration = TimeSpan.FromMilliseconds(10);
            _timer.Completed += new EventHandler(_timer_Completed);
            _timer.Begin();
             i = Convert.ToInt32(txt.Text);
        }

        private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
        {
            this.Dispatcher.BeginInvoke(new Action(() => ProgressPopup.IsOpen = true));
        }

        void _timer_Completed(object sender, EventArgs e)
        {
           
            if (i <= txt.MaxHeight)
            {
                i++;
                this.txt.Text = i.ToString();
                _timer.Begin();

                return;
            }

            this.Dispatcher.BeginInvoke(new Action(() => { ProgressPopup.IsOpen = false; }));
        }

    }