c# 如何使用 Windows.Devices.Midi 将 MIDI 消息发送到内置的 Microsoft GS Wa

我正在尝试在Windows通用应用程序中使用C#将MIDI消息发送到Windows 10上内置Microsoft GS Wavetable Synth。但是，检索 IMidiOutPort 对象 （ outputPort = await MidiOutPort.FromIdAsync(outputDevice.Id); ） 的代码始终返回 null。如何将 MIDI 消息发送到内置合成器？

在MidiInPort中使用类似的代码可以与外部MIDI键盘完美配合。不幸的是，键盘没有 MIDI，否则我会尝试发送到它以尝试缩小可能性。

附带说明一下，创建 MidiSynthesizer （MidiSynthesizer synth = await MidiSynthesizer.CreateAsync();） 的代码也返回 null。

using System;
using Windows.Devices.Enumeration;
using Windows.Devices.Midi;
using Windows.UI.Xaml.Controls;
namespace HelloMidi
{
    public sealed partial class MainPage : Page
    {
        IMidiOutPort outputPort;
        DeviceInformation outputDevice;
        DeviceInformationCollection outputDevices;
        public MainPage()
        {
            this.InitializeComponent();
            Connect();
        }
        public async void Connect()
        {
            outputDevices = await DeviceInformation.FindAllAsync(MidiOutPort.GetDeviceSelector());
            outputList.DisplayMemberPath = "Name";
            outputList.ItemsSource = outputDevices;
            outputList.SelectionMode = SelectionMode.Single;
            outputList.SelectionChanged += OutputList_SelectionChanged;
        }
        private async void OutputList_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (outputPort != null)
                outputPort.Dispose();
            if (e.AddedItems.Count > 0)
                outputDevice = (DeviceInformation)e.AddedItems[0];
            if (outputDevice != null)
                outputPort = await MidiOutPort.FromIdAsync(outputDevice.Id);
            if (outputPort != null)
                outputPort.SendMessage(new MidiStartMessage());
        }
    }
}