WPF关于MediaElement的一些有关问题

WPF关于MediaElement的一些问题
下面是xaml代码能运行！ 我想请教一下坛子里面的高手下面这个xaml用后台代码来写怎么实现？就是把下面的xaml实现的功能全部写成C#代码，怎么写？请大家给个事例。
我刚开始学习WPF

XML code

<Window x:Class="MediaPlay.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        Title="MainWindow" SizeToContent="WidthAndHeight">    <Window.Triggers>        <EventTrigger RoutedEvent="Button.Click" SourceName="BtnPlay">            <EventTrigger.Actions>                <BeginStoryboard x:Name="mbPlayer1">                    <Storyboard>                        <MediaTimeline Source="../../1002.mp3"                                       Storyboard.TargetName="mediaElement1"/>                    </Storyboard>                </BeginStoryboard>            </EventTrigger.Actions>        </EventTrigger>            <EventTrigger RoutedEvent="Button.Click" SourceName="BtnPause">            <EventTrigger.Actions>                <PauseStoryboard BeginStoryboardName="mbPlayer1"/>                <BeginStoryboard x:Name="mbPlayer2">                    <Storyboard>                        <MediaTimeline Source="../../1003.mp3" Storyboard.TargetName="mediaElement2"/>                    </Storyboard>                </BeginStoryboard>            </EventTrigger.Actions>        </EventTrigger>                <EventTrigger RoutedEvent="Button.Click" SourceName="BtnResume">            <EventTrigger.Actions>                <ResumeStoryboard BeginStoryboardName="mbPlayer1"/>                <StopStoryboard BeginStoryboardName="mbPlayer2"/>            </EventTrigger.Actions>        </EventTrigger>    </Window.Triggers>        <StackPanel HorizontalAlignment="Center" Margin="20">        <Border BorderThickness="3" Background="Black">            <Border.BorderBrush>                <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">                    <GradientStop Offset="0" Color="White"/>                    <GradientStop Offset="0.5" Color="Gold"/>                </LinearGradientBrush>            </Border.BorderBrush>            <MediaElement Width="450" x:Name="mediaElement1" LoadedBehavior="Manual"                      Volume="{Binding ElementName=volumeSlider,Path=Value}">            </MediaElement>        </Border>        <Border>            <Border.BorderBrush>                <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">                    <GradientStop Offset="0" Color="White"/>                    <GradientStop Offset="0.5" Color="Gold"/>                </LinearGradientBrush>            </Border.BorderBrush>            <MediaElement Width="450" x:Name="mediaElement2" LoadedBehavior="Manual"                      Volume="{Binding ElementName=volumeSlider,Path=Value}">            </MediaElement>        </Border>        <StackPanel Orientation="Horizontal" Height="40" HorizontalAlignment="Center">            <Button x:Name="BtnPlay" Content="Play" Style="{DynamicResource btnStyle}"/>            <Button x:Name="BtnPause" Content="Pause" Style="{DynamicResource btnStyle}"/>            <Button x:Name="BtnResume" Content="Resume" Style="{DynamicResource btnStyle}"/>        </StackPanel>        <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="5">            <TextBlock Text="Volume" Foreground="Gold"/>            <Slider x:Name="volumeSlider" Minimum="0" Maximum="1" Value="0.5" Width="200"/>        </StackPanel>    </StackPanel></Window> 
 

C# code

  private void BtnPlay_Click(object sender, RoutedEventArgs e)//BtnPlay的点击事件        {            mediaElement1.Source = new Uri(AppDomain.CurrentDomain.BaseDirectory + "media/1002.mp3");            mediaElement1.Play();        }        private void BtnPause_Click(object sender, RoutedEventArgs e)//BtnPause的点击事件        {            mediaElement1.Pause();            mediaElement2.Source = new Uri(AppDomain.CurrentDomain.BaseDirectory + "media/1003.mp3");            mediaElement2.Play();        }        private void BtnResume_Click(object sender, RoutedEventArgs e)//BtnResume的点击事件        {            mediaElement1.Play();            mediaElement2.Stop();        }