play a url in media element

private void MediaEL_MediaOpened(object sender, RoutedEventArgs e)  
02 {  
03     if (MediaEL.NaturalDuration.HasTimeSpan)  
04     {  
05         TimeSpan ts = MediaEL.NaturalDuration.TimeSpan;  
06         seekBar.Maximum = ts.TotalSeconds;  
07         seekBar.SmallChange = 1;  
08         seekBar.LargeChange = Math.Min(10, ts.Seconds / 10);  
09     }  
10     timer.Start(); 
11}
12 

public MainWindow()
{
    BoxedAppSDK.NativeMethods.BoxedAppSDK_Init();

    InitializeComponent();
}

private void button2_Click(object sender, RoutedEventArgs e)
{
    var MyFileStream = new CustomFileStream(File.ReadAllBytes(@"wildlife.wmv"));

    IntPtr ptr = BoxedAppSDK.NativeMethods.BoxedAppSDK_CreateVirtualFileBasedOnIStream(
            @"1.wmv",
            BoxedAppSDK.NativeMethods.EFileAccess.GenericWrite,
            BoxedAppSDK.NativeMethods.EFileShare.Read,
            IntPtr.Zero,
            BoxedAppSDK.NativeMethods.ECreationDisposition.New,
            BoxedAppSDK.NativeMethods.EFileAttributes.Normal,
            IntPtr.Zero,
            MyFileStream);

    using (new SafeFileHandle(ptr, true))
    {
        mediaElement1.Source = new Uri(Path.GetFullPath("1.wmv"));
        mediaElement1.LoadedBehavior = MediaState.Manual;
        mediaElement1.Play();
    }
}