C# UTC 和 Seconds(Milliseconds) 互轉

GITHUB: https://github.com/jash-git/CPP_CS_UTC2UTC2Seconds_project

code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CS_UTC2Int64
{
    class Program
    {
        static void Pause()
        {
            Console.Write("Press any key to continue...");
            Console.ReadKey(true);
        }
        static void Main(string[] args)
        {
            /*
            //https://docs.microsoft.com/zh-tw/dotnet/api/system.datetimeoffset.fromunixtimeseconds?view=net-5.0
            DateTimeOffset offset = DateTimeOffset.FromUnixTimeSeconds(20);
            Console.WriteLine("DateTimeOffset = {0}", offset);
            Console.WriteLine("DateTimeOffset (other format) = {0:dd} {0:y}, {0:hh}:{0:mm}:{0:ss}", offset);
            */

            /*        
            //https://docs.microsoft.com/zh-tw/dotnet/api/system.datetimeoffset.tounixtimeseconds?view=net-5.0
            DateTimeOffset dto = new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero);
            Console.WriteLine("{0} --> Unix Seconds: {1}", dto, dto.ToUnixTimeSeconds());

            dto = new DateTimeOffset(1969, 12, 31, 23, 59, 0, TimeSpan.Zero);
            Console.WriteLine("{0} --> Unix Seconds: {1}", dto, dto.ToUnixTimeSeconds());

            dto = new DateTimeOffset(1970, 1, 1, 0, 1, 0, TimeSpan.Zero);
            Console.WriteLine("{0} --> Unix Seconds: {1}", dto, dto.ToUnixTimeSeconds());
            */

            DateTimeOffset dto00 = new DateTimeOffset(DateTime.Now);
            Console.WriteLine("{0} --> Unix Seconds_00: {1}", dto00, dto00.ToUnixTimeSeconds());//long
            Console.WriteLine("{0} --> Unix Milliseconds_00: {1}", dto00, dto00.ToUnixTimeMilliseconds());//long

            Console.WriteLine("");

            DateTimeOffset dto01 = new DateTimeOffset(DateTime.UtcNow);//https://currentmillis.com/
            Console.WriteLine("{0} --> Unix Seconds_01: {1}", dto01, dto01.ToUnixTimeSeconds());//long
            Console.WriteLine("{0} --> Unix Milliseconds_01: {1}", dto01, dto01.ToUnixTimeMilliseconds());//long

            Pause();
        }
    }
} 

/*
2021/1/22 下午 04:14:49 +08:00 --> Unix Seconds_00: 1611303289
2021/1/22 下午 04:14:49 +08:00 --> Unix Milliseconds_00: 1611303289523

2021/1/22 上午 08:14:49 +00:00 --> Unix Seconds_01: 1611303289
2021/1/22 上午 08:14:49 +00:00 --> Unix Milliseconds_01: 1611303289526
Press any key to continue...
*/