Windows Phone 7 程式功能表列ApplicationBar

ApplicationBar控制項時windows phone 7上的一個菜單，它傳統的Windows程式的菜單的作用類似。
ApplicationBar（ApplicationBarIconButton和ApplicationBarMenuItem）相關的類定義在Microsoft.Phone.Shell命名空間。與UIElement和FrameworkElement等常規Silverlight編程的類層次是完全分開的，嚴格說來ApplicationBar不是你的頁面的可視化的一部分。
一個ApplicationBar最多可包含四個按鈕。如果還有額外的選項可以通過功能表項目來添加，這些功能表項目預設是不顯示的。只有在點擊功能表列右側的省略符號(或省略符號下方的地區)時才會顯示出來。

該項目包含一個MediaElement MoviePlayer播放影片，而ApplicationBar包含第一，播放，暫停，最後四個選項。

<!--LayoutRoot contains the root grid where all other page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>

<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock x:Name="ApplicationTitle" Text="MOVIE PLAYER" Style="{StaticResource PhoneTextNormalStyle}"/>
</StackPanel>

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<MediaElement Name="mediaElement" 
                          Source="http://localhost/123.wmv"
                          AutoPlay="False"
                          MediaOpened="OnMediaElementMediaOpened"
                          MediaFailed="OnMediaElementMediaFailed"
                          CurrentStateChanged="OnMediaElementCurrentStateChanged"  />

<TextBlock Name="statusText"
                       HorizontalAlignment="Left"
                       VerticalAlignment="Bottom" />

<TextBlock Name="errorText"
                       HorizontalAlignment="Right"
                       VerticalAlignment="Bottom"
                       TextWrapping="Wrap" />
</Grid>
</Grid>

<phone:PhoneApplicationPage.ApplicationBar>
<shell:ApplicationBar>
<shell:ApplicationBarIconButton 
x:Name="appbarRewindButton"
                    IconUri="Images/appbar.transport.rew.rest.png" 
                    Text="rewind"
                    IsEnabled="False"
                    Click="OnAppbarRewindClick" />

<shell:ApplicationBarIconButton 
x:Name="appbarPlayButton"
                    IconUri="Images/appbar.transport.play.rest.png" 
                    Text="play"
                    IsEnabled="False"
                    Click="OnAppbarPlayClick" />

<shell:ApplicationBarIconButton
x:Name="appbarPauseButton"
                    IconUri="Images/appbar.transport.pause.rest.png" 
                    Text="pause"
                    IsEnabled="False"
                    Click="OnAppbarPauseClick" />

<shell:ApplicationBarIconButton
x:Name="appbarEndButton"
                    IconUri="Images/appbar.transport.ff.rest.png" 
                    Text="to end"
                    IsEnabled="False"
                    Click="OnAppbarEndClick" />
</shell:ApplicationBar>
</phone:PhoneApplicationPage.ApplicationBar>

View Code

using System;
using System.Windows;
using System.Windows.Media;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;

namespace MoviePlayer
{
public partial class MainPage : PhoneApplicationPage
    {
// Constructor
        public MainPage()
        {
            InitializeComponent();

// Re-assign names already in the XAML file
            appbarRewindButton = this.ApplicationBar.Buttons[0] as ApplicationBarIconButton;
            appbarPlayButton = this.ApplicationBar.Buttons[1] as ApplicationBarIconButton;
            appbarPauseButton = this.ApplicationBar.Buttons[2] as ApplicationBarIconButton;
            appbarEndButton = this.ApplicationBar.Buttons[3] as ApplicationBarIconButton;
        }

// ApplicationBar buttons
        void OnAppbarRewindClick(object sender, EventArgs args)
        {
            mediaElement.Position = TimeSpan.Zero;
        }

void OnAppbarPlayClick(object sender, EventArgs args)
        {
            mediaElement.Play();
        }

void OnAppbarPauseClick(object sender, EventArgs args)
        {
            mediaElement.Pause();
        }

void OnAppbarEndClick(object sender, EventArgs args)
        {
            mediaElement.Position = mediaElement.NaturalDuration.TimeSpan;
        }

// MediaElement events
        void OnMediaElementMediaFailed(object sender, ExceptionRoutedEventArgs args)
        {
            errorText.Text = args.ErrorException.Message;
        }

void OnMediaElementMediaOpened(object sender, RoutedEventArgs args)
        {
            appbarRewindButton.IsEnabled = true;
            appbarEndButton.IsEnabled = true;
        }

void OnMediaElementCurrentStateChanged(object sender, RoutedEventArgs args)
        {
            statusText.Text = mediaElement.CurrentState.ToString();

if (mediaElement.CurrentState == MediaElementState.Stopped ||
                mediaElement.CurrentState == MediaElementState.Paused)
            {
                appbarPlayButton.IsEnabled = true;
                appbarPauseButton.IsEnabled = false;
            }
else if (mediaElement.CurrentState == MediaElementState.Playing)
            {
                appbarPlayButton.IsEnabled = false;
                appbarPauseButton.IsEnabled = true;
            }
        }
    }
}