WPF 控件开发之MediaElement

MediaElement的暂停，播放功能。

<UserControl x:Class="Control_Test.MediaElement"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <UserControl.Resources>
        <ImageBrush  x:Key="StartImgBrush" ImageSource="Chapter02/player_start.png"/>
        <ImageBrush  x:Key="PauseImgBrush" ImageSource="Chapter02/player_pause.png"/>
        <ImageBrush x:Key="PlayImgBrush" ImageSource="Chapter02/player_play.png"/>
        <ImageBrush x:Key="StopImgBrush" ImageSource="Chapter02/player_stop.png"/>     
        <!--Button控件模板-->
        <ControlTemplate x:Key="ButtonTemplate" TargetType="Button">
            <Grid>
                <Rectangle x:Name="Rect" Fill="{TemplateBinding Background}"/>
            </Grid>
        </ControlTemplate>    
        <ControlTemplate x:Key="PlayButtonTemplate" TargetType="ToggleButton">
            <Grid>
                <Rectangle x:Name="Rect" Fill="{StaticResource PlayImgBrush}"/>
            </Grid>
            <ControlTemplate.Triggers>
                <Trigger Property="ToggleButton.IsChecked" Value="True">
                    <Setter Property="Fill" Value="{StaticResource PauseImgBrush}" TargetName="Rect">                  
                    </Setter>
                </Trigger>
                <Trigger Property="ToggleButton.IsChecked" Value="False">
                    <Setter Property="Fill" Value="{StaticResource PlayImgBrush}" TargetName="Rect">
                    </Setter>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </UserControl.Resources>
    <UserControl.CommandBindings>
        <CommandBinding Command="MediaCommands.TogglePlayPause" CanExecute="CommandBinding_CanExecute" Executed="PlayPause"/>
        <CommandBinding Command="MediaCommands.Stop" CanExecute="CommandBinding_CanExecute" Executed="Stop"/>
        <CommandBinding Command="MediaCommands.Rewind" CanExecute="CommandBinding_CanExecute" Executed="Stop"/>
    </UserControl.CommandBindings>
    <DockPanel>    
        <Grid DockPanel.Dock="Bottom">
            <Border Width="180" Height="24" 
                    Background="LightGray"
                    BorderBrush="DarkGray" 
                    BorderThickness="1" 
                    CornerRadius="12"
                    SnapsToDevicePixels="False"></Border>
            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
                <Button  Width="32" Height="32" 
                         Command="MediaCommands.Rewind"
                         Template="{StaticResource ButtonTemplate}"
                         Background="{StaticResource StartImgBrush}">Rewind</Button>
                <ToggleButton x:Name="_playBtn" Width="48" Height="48" Margin="10,0,10,0"
                              Command="MediaCommands.TogglePlayPause"
                              Template="{StaticResource PlayButtonTemplate}"/>
                <Button  Width="32" Height="32" 
                         Command="MediaCommands.Stop"
                         Template="{StaticResource ButtonTemplate}"
                         Background="{StaticResource StopImgBrush}">Stop</Button>
            </StackPanel>
        </Grid>
        <MediaElement x:Name="myMedia" LoadedBehavior="Manual" UnloadedBehavior="Pause" Source="E:/Bear.wmv"/>
    </DockPanel>
</UserControl>

C#Code

        private void CommandBinding_CanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = true;
        }

        private void PlayPause(object sender, ExecutedRoutedEventArgs e)
        {
            if(_isPlaying)
            {
                myMedia.Pause();
                _isPlaying = false;
            }
            else
            {
                myMedia.Play();
                _isPlaying = true;
            }
        }

        private void Stop(object sender, ExecutedRoutedEventArgs e)
        {
            myMedia.Stop();
            _playBtn.IsChecked = false;
            _isPlaying = false;

        }