c# - Working with MIDI in Windows Store App (Win 8.1) -

my goal receive midi messages in windows store apps. microsoft has delivered api called microsoft.windowspreview.midirt (as nuget package).

i managed midi port, messagereceived event not arised, although i'm pressing keys on midi keyboard, , other midi programs show me pc receives these messages.

here code:

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);     } } 

any ideas?

possibly-related: device watcher code not following normal pattern. here need do:

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}' id {1} added", a.name, a.id);   midiwatcher.updated += (s, a) => debug.writeline("midi port id {1} updated", a.id);   midiwatcher.removed += (s, a) => debug.writeline("midi port id {1} removed", a.id);   midiwatcher.enumerationcompleted += (s, a) => debug.writeline("initial enumeration complete; watching changes...");    midiwatcher.start(); }