# Pausing, Stopping, or Playing Media in Silverlight MediaElements

ID: SL12

Technology: silverlight

Type: Technique

## When to Use

- Microsoft Silverlight, versions 3 and greater
- Silverlight managed programming model and Silverlight XAML

## Description

The objective of this technique is to create a control user interface for the Silverlight `MediaElement` object. The controls enable users to pause or stop the video to prevent the video images on the `MediaElement` surface from moving, and stop video-associated audio. These UI controls enable an interaction defined in code event handlers. Each handler calls one of the following `MediaElement` methods:

- Pause
- Play
- Stop

Note that by default, a `MediaElement` will start playing its media as soon as the UI loads completely AND the media source file is downloaded (or a certain buffer size is reached, in the case of streaming media). Use the `AutoPlay` property to change this default.

## Examples

### Providing MediaElement controls in the UI

This example has a UI definition in XAML and interaction logic in C#.

    <UserControl x:Class="MediaElementControls.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     >
      <Grid x:Name="LayoutRoot">
          <StackPanel>
              <MediaElement x:Name="media" Source="/xbox.wmv"
             Width="300" Height="300"
             AutomationProperties.Name="Video of new Fable game for XBox"
          />
              <Grid Name="UIControls">
                  <Grid.ColumnDefinitions>
                      <ColumnDefinition Width="*" />
                      <ColumnDefinition Width="*" />
                      <ColumnDefinition Width="*"/>
                  </Grid.ColumnDefinitions>
                  <Grid.RowDefinitions>
                      <RowDefinition Height="*" />
                      <RowDefinition Height="Auto" />
                      <RowDefinition Height="20" />
                  </Grid.RowDefinitions>
                  <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" />
                  <Button Click="MuteMedia"
      Grid.Row="2" Grid.Column="0" Content="Mute" />
                  <TextBlock Name="VolumeLabel" Grid.Row="2" Grid.Column="1" HorizontalAlignment="Right">Volume</TextBlock>
                  <Slider Height="20"
              Value="{Binding Volume, Mode=TwoWay, ElementName=media}"
              Minimum="0" Maximum="1"
              Grid.Row="2" Grid.Column="2" Grid.ColumnSpan="2"
                  AutomationProperties.LabeledBy="{Binding ElementName=VolumeLabel}"/>
              </Grid>
          </StackPanel>
      </Grid>
    </UserControl>

    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();
    }
    private void MuteMedia(object sender, RoutedEventArgs e)
    {
        Button target = sender as Button;
        // mute if not muted, unmute if already muted, in either case make sure the button content for text and accessibility info is updated
        if (!media.IsMuted)
        {
            media.IsMuted = true;
            target.Content = "Unmute";
        }
        else
        {
             media.IsMuted = false;
             target.Content = "Mute";
         }
    }

This example is shown in operation in the working example of Media Element Controls.

## Tests

### Procedure

1. Using a browser that supports Silverlight, open an HTML page that references a Silverlight application through an object tag. The application is expected to incorporate a `MediaElement` in the user interface.
2. Check that interactive controls are available so that users can pause or stop the media.
3. Check that when activated, the controls stop or pause the media.

### Expected Results

#2 and #3 are true.

## Related Techniques

- SL17
- SL24

## Resources

- 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`