Technique SL24:Using AutoPlay to Keep Silverlight Media from Playing Automatically
About this Technique
This technique is not referenced from any Understanding document.
This technique applies to content implemented in Microsoft Silverlight.
Description
The objective of this technique is to use the AutoPlay
property
of MediaElement
object, which prevents the MediaElement
from
playing its media source automatically.
By default the value of AutoPlay
is true, which causes
any media that is the Source
of the MediaElement
to
play as soon as either the entire source file is loaded (for nonstreaming
media) or an initial buffer is loaded (for streaming media). To prevent
the possible accessibility issues, developers can instead specifically set AutoPlay
to
false, so that the user always controls whether the media plays. This
technique would thus be used in combination with providing user interface
controls that go along with the MediaElement
, and
that enable the user to control the media. In particular, the user
interface controls enable the media to play, pause or stop, with event
wiring for those controls associated with the Play, Pause or Stop methods
of the MediaElement
object.
Examples
Example 1: Setting AutoPlay to false, and providing the typical MediaElement controls in the UI
This example has a UI definition in XAML and interaction logic in C#.
The following is the basic UI in XAML. Note the AutoPlay="false" setting.
<UserControl x:Class="MediaElementControlsAutoPlay.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" > <Grid x:Name="LayoutRoot"> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="*" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <MediaElement x:Name="media" Source="/xbox.wmv" Width="300" Height="300" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="3" AutoPlay="False" AutomationProperties.Name="Video of new Fable game for XBox" /> <Button Click="StopMedia" Grid.Column="0" Grid.Row="1" Content="Stop" /> <Button Click="PauseMedia" Grid.Column="1" Grid.Row="1" Content="Pause" /> <Button Click="PlayMedia" Grid.Column="2" Grid.Row="1" Content="Play" /> </Grid> </UserControl>
The following is the C# logic.
private void StopMedia(object sender, RoutedEventArgs e) { media.Stop(); } private void PauseMedia(object sender, RoutedEventArgs e) { media.Pause(); } private void PlayMedia(object sender, RoutedEventArgs e) { media.Play(); }
This example is shown in operation in the working example of Media Element Controls with AutoPlay False.
Related Resources
No endorsement implied.
- Audio and Video Overview
- MediaElement Class
-
Silverlight
Media Framework - a framework and a media player control implementation
that incorporates many of the Silverlight techniques related to
MediaElement
Tests
Procedure
- Using a browser that supports Silverlight, open an HTML page that
references a Silverlight application through an object tag. The application
is expected to use a
MediaElement
object to play prerecorded media. - Check that the media does not play automatically as soon as the application loads and displays. Rather, the user is presented with a user interface that can start the media per the user's action.
Expected Results
#2 is true.