Question

I have built a simple game in WP7 and I am trying to add background music to it using MediaPlayer. The problem is it just bombs with

{“An unexpected error has occurred.”} System.Exception {System.InvalidOperationException}

Code

try
                {
                    MediaPlayer.Stop();
                    // Timer to run the XNA internals (MediaPlayer is from XNA)
                    DispatcherTimer dt = new DispatcherTimer();
                    dt.Interval = TimeSpan.FromMilliseconds(33);
                    dt.Tick += delegate { try { FrameworkDispatcher.Update(); } catch { } };
                    dt.Start();

                    Uri pathToFile = new Uri("Audio/music.m4a", UriKind.Relative);
                    Song playingSong = Song.FromUri("Music", pathToFile);
                    MediaPlayer.Play(playingSong);
                }
                catch (Exception e)
                {
                    musicFailed = true;
                    Console.WriteLine("Exception: {0}", e.ToString());
                    MessageBox.Show("Warning, music failed to play however you can still continue to play your game.");
                }
            }

I tried a few tweaks, converting file to mp3, different paths etc. The file is marked for copy always and content type I also tried removing the Dispatcher as dont know what that is for.

Answer 1

If you can convert your audio files to WAV format, you can try using the XNA SoundEffect and SoundEffectInstance classes:

SoundEffect se = SoundEffect.FromStream(isolatedStorageFileStream);
SoundEffectInstance sei = se.CreateInstance();
sei.Play();

For this to work, you will need to reference the XNA library (Microsoft.XNA.Framework) and initialize the framework in this way:

App.xaml:

<Application>
    <Application.ApplicationLifetimeObjects>
        <local:XNAFrameworkDispatcherService />
        ...
    </Application.ApplicationLifetimeObjects>    
</Application>

And create this class somewhere in the app namespace (“local” in the previous xaml references this namespace):

public class XNAFrameworkDispatcherService : IApplicationService
{
    private DispatcherTimer frameworkDispatcherTimer;
    public XNAFrameworkDispatcherService()
    {
        this.frameworkDispatcherTimer = new DispatcherTimer();
        this.frameworkDispatcherTimer.Interval = TimeSpan.FromTicks(333333);
        this.frameworkDispatcherTimer.Tick += frameworkDispatcherTimer_Tick;
        FrameworkDispatcher.Update();
    }
    void frameworkDispatcherTimer_Tick(object sender, EventArgs e) { FrameworkDispatcher.Update(); }
    void IApplicationService.StartService(ApplicationServiceContext context) { this.frameworkDispatcherTimer.Start(); }
    void IApplicationService.StopService() { this.frameworkDispatcherTimer.Stop(); }
}