header.hpp

extern "C"
{
	struct PluginVector3
	{
		double x;
		double y;
		double z;
	};
	
	__declspec (dllexport) HRESULT Initialize();
	__declspec (dllexport) HRESULT Uninitialize();
	__declspec (dllexport) PluginVector3 GetAccelerometer();
	__declspec (dllexport) PluginVector3 GetAngularAcceleration();
}

mainwindow.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Threading;

namespace GyroWpfApp
{
    /// <summary>
    /// MainWindow.xaml の相互作用ロジック
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            Sensors.Initialize();
            var timer = new DispatcherTimer();
            timer.Tick += (_, __) =>
                {
                    var v = Sensors.GetAngularAcceleration();
                    this.TextBlockX.Text = v.x.ToString();
                    this.TextBlockY.Text = v.y.ToString();
                    this.TextBlockZ.Text = v.z.ToString();
                };
            timer.Interval = TimeSpan.FromSeconds(1);
            timer.Start();
        }

    }

    public static class Sensors
    {
        [DllImport("Sensors.dll"), CallingConvention=CallingConvention.Cdecl ]
        public static extern uint Initialize();
        [DllImport("Sensors.dll"), CallingConvention=CallingConvention.Cdecl ]
        public static extern uint Uninitialize();
        [DllImport("Sensors.dll"), CallingConvention=CallingConvention.Cdecl ]
        public static extern PluginVector3 GetAngularAcceleration();
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PluginVector3
    {
        public double x;
        public double y;
        public double z;
    }
}

source.cpp

// Win32Project1.cpp : DLL アプリケーション用にエクスポートされる関数を定義します。
//
#include "stdafx.h"
#include <InitGuid.h>
#include <SensorsApi.h>
#include <Sensors.h>
#pragma comment(lib, "Sensorsapi.lib")

#define SAFE_RELEASE(x) {if(x){x->Release(); x=nullptr;}}

ISensorManager* pSensorManager;
ISensor* pMotionSensor;
ISensor* pGyrometerSensor;

HRESULT InitializeAccelerometerSensor()
{
	ISensorCollection *pMotionSensorCollection;
	if (!SUCCEEDED(pSensorManager->GetSensorsByCategory(SENSOR_TYPE_ACCELEROMETER_3D, &pMotionSensorCollection)))
	{
		return E_ERROR;
	}
	if (!SUCCEEDED(pMotionSensorCollection->GetAt(0, &pMotionSensor)))
	{
		pMotionSensorCollection->Release();
		return E_ERROR;
	}
	pMotionSensorCollection->Release();
	return S_OK;
}

HRESULT InitializeGyrometerSensor()
{
	ISensorCollection *pGyrometerSensorCollection;
	if (!SUCCEEDED(pSensorManager->GetSensorsByCategory(SENSOR_TYPE_GYROMETER_3D, &pGyrometerSensorCollection)))
	{
		return E_ERROR;
	}
	if (!SUCCEEDED(pGyrometerSensorCollection->GetAt(0, &pGyrometerSensor)))
	{
		pGyrometerSensorCollection->Release();
		return E_ERROR;
	}
	pGyrometerSensorCollection->Release();
	return S_OK;
}

__declspec (dllexport) HRESULT Initialize()
{
	// Initialize ISensorManager
	if (!SUCCEEDED(::CoCreateInstance(CLSID_SensorManager, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pSensorManager))))
	{
		return E_ERROR;
	}
	// Initialize Accelerometer Sensor
	if (FAILED(InitializeAccelerometerSensor()))
	{
		SAFE_RELEASE(pSensorManager);
		return E_ERROR;
	}
	// Initialize Gyrometer Sensor
	if (FAILED(InitializeGyrometerSensor()))
	{
		SAFE_RELEASE(pMotionSensor);
		SAFE_RELEASE(pSensorManager);
		return E_ERROR;
	}
	return S_OK;
}

__declspec (dllexport) HRESULT Uninitialize()
{
	SAFE_RELEASE(pSensorManager);
	SAFE_RELEASE(pMotionSensor);
	SAFE_RELEASE(pGyrometerSensor);
	return S_OK;
}

__declspec (dllexport) PluginVector3 GetAccelerometer()
{
	ISensorDataReport *pData;
	if (!pMotionSensor || !SUCCEEDED(pMotionSensor->GetData(&pData)))
	{
		return PluginVector3();
	}

	PROPVARIANT x = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_X_G, &x)))
	{
		pData->Release();
		return PluginVector3();
	}
	PROPVARIANT y = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Y_G, &y)))
	{
		pData->Release();
		return PluginVector3();
	}
	PROPVARIANT z = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ACCELERATION_Z_G, &z)))
	{
		pData->Release();
		return PluginVector3();
	}

	pData->Release();

	PluginVector3 v;
	v.x = x.dblVal;
	v.y = y.dblVal;
	v.z = z.dblVal;
	return v;
}

__declspec (dllexport) PluginVector3 GetAngularAcceleration()
{
	ISensorDataReport *pData;
	if (!pGyrometerSensor || !SUCCEEDED(pGyrometerSensor->GetData(&pData)))
	{
		return{ -4, -4, -4 };
	}

	PROPVARIANT x = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ANGULAR_VELOCITY_X_DEGREES_PER_SECOND, &x)))
	{
		pData->Release();
		return{ -5, -5, -5 };
	}
	PROPVARIANT y = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ANGULAR_VELOCITY_Y_DEGREES_PER_SECOND, &y)))
	{
		pData->Release();
		return{ -6, -6, -6 };
	}
	PROPVARIANT z = {};
	if (!SUCCEEDED(pData->GetSensorValue(SENSOR_DATA_TYPE_ANGULAR_VELOCITY_Z_DEGREES_PER_SECOND, &z)))
	{
		pData->Release();
		return{ -7, -7, -7 };
	}

	pData->Release();

	PluginVector3 v;
	v.x = x.dblVal;
	v.y = y.dblVal;
	v.z = z.dblVal;
	return v;
}