Sharing Media Playback Between Pages with Windows Phone 7 Media Player

What I want to achieve:

• I want to initiate audio playback from an mp3 and/or aac HTTP stream in a WP7 application
• I want to initiate playback from a specific 'PhoneApplicationPage' instance, but still allow navigation to other pages whilst maintaining playback without any interuption - i.e. I want playback to be 'application-scope'
• I want to be able to 'seek' within my media
• I playback to continue whilst the phone is locked

What I have tried:

MediaElement:

• If the MediaElement is not owned by a page, no sound is produced when Play() is called, despite no exceptions being thrown.
• After following 'http://blog.jayway.com/2010/10/04/enable-background-audio-for-multiple-pages-in-windows-phone-7/', playback still resets between page transitions
• It also seems like a quite a hacky way of doing things...

Microsoft.Xna.Framework.MediaPlayer:

• Works, but "MediaPlayer.PlayPosition" is read-only, and there is no seek method.
• See post: 'http://forums.create.msdn.com/forums/t/17318.aspx' - Apparently this is by design due to 开发者_JS百科XBox constraints with Xna (?!)

Microsoft Silverlight Media Framework:

• http://smf.codeplex.com/
• My favourite option, as it seems very comprehensive
• Downloaded 'Silverlight Media Framework 2.3, WP7 specific' assemblies from: http://smf.codeplex.com/releases/view/57991#DownloadId=190196
• I know this is hacky, but to get something working, in the code below, the 'SMFPlayer' is static, and added to each page's layout on navigation.
• If the 'SMFPlayer' is not owned by a page, no sound is produced when Play() is called, despite no exceptions being thrown.
• Playback still resets between page transitions...
• Code:

using System;
using System.Diagnostics;
using Microsoft.Phone.Controls;
using Microsoft.SilverlightMediaFramework.Core;
using Microsoft.SilverlightMediaFramework.Core.Media;
using Microsoft.SilverlightMediaFramework.Plugins.Primitives;

namespace WindowsPhoneApplication1
{
    public partial class MainPage : PhoneApplicationPage
    {
        public static readonly SMFPlayer Player = new SMFPlayer();

        static MainPage()
        {
            Player.VolumeLevel = 1.0f;
            Player.Playlist.Add(new PlaylistItem {MediaSource = new Uri("http://smf.vertigo.com/videos/wildlife.wmv", UriKind.Absolute)});

            Player.LogLevel = LogLevel.All;
            Player.LogEntryReceived += PlayerLogEntryReceived;
        }

        // Constructor
        public MainPage()
        {
            InitializeComponent();
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            LayoutRoot.Children.Add(Player);
        }

        protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)
        {
            base.OnNavigatingFrom(e);
            LayoutRoot.Children.Remove(Player);
        }

        private static void PlayerLogEntryReceived(object sender, CustomEventArgs<LogEntry> e)
        {
            Debug.WriteLine(e.Value.Severity + e.Value.Message + e.Value.Type);
        }

        private void button1_Click(object sender, System.Windows.RoutedEventArgs e)
        {
            this.NavigationService.Navigate(new Uri("/Page1.xaml", UriKind.RelativeOrAbsolute));
        }
    }
}

Does anyone have any idea how I can satisfy my requirements? Example code?

From an architectural point of view, what I really want is a Media Service which i can send streaming URLs to without caring about which page is currently shown.

---

I eventually found a simple, but effective solution: http://blog.reis.se/post/Enable-background-audio-for-multiple-pages-in-Windows-Phone-7-e28093-Take-2.aspx

In App.xaml:

<APPLICATION.RESOURCES>
    <MEDIAELEMENT x:key="GlobalMedia"></MEDIAELEMENT>
</APPLICATION.RESOURCES>

In App.xaml.cs:

public static MediaElement GlobalMediaElement
{
  get { return Current.Resources["GlobalMedia"] as MediaElement; }
}

In your page:

public partial class MyPage : PhoneApplicationPage
{
    MediaElement MEAudio;

    public MainPage()
    {
        InitializeComponent();    
        MEAudio = App.GlobalMediaElement;
    }

    private void OnSomeEvent(object sender, RoutedEventArgs e)
    {
        MEAudio.xxxxx();