WriteOnceBlock

只写入一次，第二次post不再生效，不再写入

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

namespace WriteOnceBlockDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            TestSync();
            Console.Read();
        }
        static WriteOnceBlock<int> bb = new WriteOnceBlock<int>((i) => { return i; });

        static ActionBlock<int> displayBlock = new ActionBlock<int>((i) => Console.WriteLine("Displayed " + i));

        static ActionBlock<int> saveBlock = new ActionBlock<int>((i) => Console.WriteLine("Saved " + i));

        static ActionBlock<int> sendBlock = new ActionBlock<int>((i) => Console.WriteLine("Sent " + i));

        public static void TestSync()
        {
            bb.LinkTo(displayBlock);
            bb.LinkTo(saveBlock);
            bb.LinkTo(sendBlock);
            for (int i = 0; i < 4; i++)
            {
                bb.Post(i);
            }

            Console.WriteLine("Post finished");
        }
    }
}