Windows 7 new features: Step by step in VB.NET and C#

// Copyright (c) Microsoft Corporation.  All rights reserved.

using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Globalization;
using WORD = System.UInt16;
using MS.WindowsAPICodePack.Internal;
using Microsoft.WindowsAPICodePack.Shell.PropertySystem;

namespace Microsoft.WindowsAPICodePack.Sensors
{
    /// <summary>
    /// The SYSTEMTIME structure represents a date and time using individual members for 
    /// the month, day, year, weekday, hour, minute, second, and millisecond.
    /// </summary>
    [StructLayout( LayoutKind.Sequential )]
    internal struct SYSTEMTIME
    {
        public WORD wYear;
        public WORD wMonth;
        public WORD wDayOfWeek;
        public WORD wDay;
        public WORD wHour;
        public WORD wMinute;
        public WORD wSecond;
        public WORD wMillisecond;

        /// <summary>
        /// Gets the <see cref="DateTime"/> representation of this object.
        /// </summary>
        public DateTime DateTime
        {
            get { return new DateTime( wYear, wMonth, wDay, wHour, wMinute, wSecond, wMillisecond ); }
        }

        public static implicit operator DateTime( SYSTEMTIME systemTime )
        {
            return systemTime.DateTime;
        }

        public override string ToString( )
        {
            return string.Format( CultureInfo.InvariantCulture.NumberFormat, "{0:D2}/{1:D2}/{2:D4}, {3:D2}:{4:D2}:{5:D2}.{6}", wMonth, wDay, wYear, wHour, wMinute, wSecond, wMillisecond );
        }
    }

    /// <summary>
    /// COM interop wrapper for the ISensorDataReport interface.
    /// </summary>
    [ComImport, Guid( "0AB9DF9B-C4B5-4796-8898-0470706A2E1D" ), InterfaceType( ComInterfaceType.InterfaceIsIUnknown )]
    internal interface ISensorDataReport
    {
        /// <summary>
        /// Get the timestamp for the data report
        /// </summary>
        /// <param name="timeStamp">The timestamp returned for the data report</param>
        void GetTimestamp(out SYSTEMTIME timeStamp);

        /// <summary>
        /// Get a single value reported by the sensor
        /// </summary>
        /// <param name="propKey">The data field ID of interest</param>
        /// <param name="propValue">The data returned</param>
        void GetSensorValue(
            [In] ref PropertyKey propKey,
            [In, Out] PropVariant propValue); // value must be newed before call

        /// <summary>
        /// Get multiple values reported by a sensor
        /// </summary>
        /// <param name="keys">The collection of keys for values to obtain data for</param>
        /// <param name="values">The values returned by the query</param>
        void GetSensorValues(
            [In, MarshalAs(UnmanagedType.Interface)] IPortableDeviceKeyCollection keys,
            [Out, MarshalAs(UnmanagedType.Interface)] out IPortableDeviceValues values);
    }
}