WP7备注(24)(ApplicationBar|MediaElement)

ApplicationBar常规用法:

<shell:ApplicationBar IsVisible="False">

<shell:ApplicationBarIconButton
IconUri="Images/appbar.transport.pause.rest.png"
Text="Pause"
IsEnabled="False"
Click="OnAppBarPauseClick" />

(this.ApplicationBar.Buttons[1] as ApplicationBarIconButton).IsEnabled = false;

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MediaElement控制实例:

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<MediaElement Name="mediaElement"
Source="http://www.charlespetzold.com/Media/Walrus.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>

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;
}

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;
}

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;
}
}