使用MIDI在Windows商店应用程序(Win 8.1)

我的目标是在Windows Store应用程序中接收MIDI消息。微软已经交付了一个名为Microsoft.WindowsPreview.MidiRT的API(作为一个nuget包)。

我设法得到一个midi端口，但MessageReceived事件没有出现，虽然我在我的midi键盘上按键，其他midi程序显示我PC接收这些消息。

下面是我的代码:

public sealed partial class MainPage : Page
{
    private MidiInPort port;
    public MainPage()
    {
        this.InitializeComponent();
        DeviceWatcher watcher = DeviceInformation.CreateWatcher();
        watcher.Updated += watcher_Updated;
        watcher.Start();
    }
    protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
    {
        base.OnNavigatingFrom(e);
        port.Dispose();
    }
    async void watcher_Updated(DeviceWatcher sender, DeviceInformationUpdate args)
    {
        DeviceInformationCollection deviceCollection = await DeviceInformation.FindAllAsync(MidiInPort.GetDeviceSelector());
        foreach (var item in deviceCollection)
        {
            Debug.WriteLine(item.Name);
            if (port == null)
            {
                port = await MidiInPort.FromIdAsync(item.Id);
                port.MessageReceived += port_MessageReceived;
            }
        }
    }
    void port_MessageReceived(MidiInPort sender, MidiMessageReceivedEventArgs args)
    {
        Debug.WriteLine(args.Message.Type);
    }
}

任何想法?

DeviceWatcher midiWatcher;
void MonitorMidiChanges()
{
  if (midiWatcher != null)
    return;
  var selector = MidiInPort.GetDeviceSelector();
  midiWatcher = DeviceInformation.CreateWatcher(selector);
  midiWatcher.Added += (s, a) => Debug.WriteLine("Midi Port named '{0}' with Id {1} was added", a.Name, a.Id);
  midiWatcher.Updated += (s, a) => Debug.WriteLine("Midi Port with Id {1} was updated", a.Id);
  midiWatcher.Removed += (s, a) => Debug.WriteLine("Midi Port with Id {1} was removed", a.Id);
  midiWatcher.EnumerationCompleted += (s, a) => Debug.WriteLine("Initial enumeration complete; watching for changes...");
  midiWatcher.Start();
}