问如何在C#中使用GetTimeFormat接口

EN

DateTime.ToString(string format, IFormatProvider provider);

using System;
using System.Text;
using System.Runtime.InteropServices;

class Core
{
    public static void Main(string[] args)
    {
        SystemTime MySystemTime = new SystemTime(DateTime.Now);
        StringBuilder MyStringBuilder = new StringBuilder();

        int Result = GetTimeFormat(0, 0, ref MySystemTime, "hh':'mm':'ss", MyStringBuilder, 128);

        uint ErrorCode = GetLastError(); // Reference: https://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx

        Console.ReadKey(true);  
    }

    [DllImport("kernel32.dll")]
    static extern int GetTimeFormat(uint locale, uint dwFlags, ref SystemTime time, string format, StringBuilder sb, int sbSize);

    [DllImport("kernel32.dll")]
    public static extern uint GetLastError();

    [StructLayout(LayoutKind.Sequential, Pack = 2)]
    internal struct SystemTime
    {
        public ushort Year;
        public ushort Month;
        public ushort DayOfWeek;
        public ushort Day;
        public ushort Hour;
        public ushort Minute;
        public ushort Second;
        public ushort Milliseconds;

        public SystemTime(DateTime dt)
        {
            dt = dt.ToUniversalTime();
            Year = Convert.ToUInt16(dt.Year);
            Month = Convert.ToUInt16(dt.Month);
            DayOfWeek = Convert.ToUInt16(dt.DayOfWeek);
            Day = Convert.ToUInt16(dt.Day);
            Hour = Convert.ToUInt16(dt.Hour);
            Minute = Convert.ToUInt16(dt.Minute);
            Second = Convert.ToUInt16(dt.Second);
            Milliseconds = Convert.ToUInt16(dt.Millisecond);
        }

        public SystemTime(ushort year, ushort month, ushort day, ushort hour = 0, ushort minute = 0, ushort second = 0, ushort millisecond = 0)
        {
            Year = year;
            Month = month;
            Day = day;
            Hour = hour;
            Minute = minute;
            Second = second;
            Milliseconds = millisecond;
            DayOfWeek = 0;
        }

        public static implicit operator DateTime(SystemTime st)
        {
            if (st.Year == 0 || st == MinValue)
                return DateTime.MinValue;
            if (st == MaxValue)
                return DateTime.MaxValue;
            return new DateTime(st.Year, st.Month, st.Day, st.Hour, st.Minute, st.Second, st.Milliseconds, DateTimeKind.Local);
        }

        public static bool operator ==(SystemTime s1, SystemTime s2)
        {
            return (s1.Year == s2.Year && s1.Month == s2.Month && s1.Day == s2.Day && s1.Hour == s2.Hour && s1.Minute == s2.Minute && s1.Second == s2.Second && s1.Milliseconds == s2.Milliseconds);
        }

        public static bool operator !=(SystemTime s1, SystemTime s2)
        {
            return !(s1 == s2);
        }

        public static readonly SystemTime MinValue, MaxValue;

        static SystemTime()
        {
            MinValue = new SystemTime(1601, 1, 1);
            MaxValue = new SystemTime(30827, 12, 31, 23, 59, 59, 999);
        }

        public override bool Equals(object obj)
        {
            if (obj is SystemTime)
                return ((SystemTime)obj) == this;
            return base.Equals(obj);
        }

        public override int GetHashCode()
        {
            return base.GetHashCode();
        }
    }
}