并发字典ConcurrentDictionary+迭代器--异步

并发字典ConcurrentDictionary+迭代器--异步

代码如下：

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
 
namespace EFCOREDB
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            #region
             //GetAsync();

            //var iterator = GetEnumerator();
            //while (iterator.MoveNext())
            //{
            //    Console.WriteLine($"输出{iterator.Current}");
            //}
            #region 测试
            //TestConcurrentDictionary(); 
            #endregion
            Console.Read();
        }
#region 测试并发字典ConcurrentDictionary+迭代器--异步
        /// <summary>
        /// 迭代器--异步
        /// </summary>
        /// <returns></returns>
        static async void GetAsync()
        {
            var iterator = GetEnumeratorAsyncFor();
            while (await iterator.MoveNextAsync())
            {
                Console.WriteLine($"输出{iterator.Current}");
            }
            #region MyRegion
            //var iterator = GetEnumeratorAsync();
            //    var result = await iterator.MoveNextAsync();
            //    while (result)
            //    {
            //        Console.WriteLine($"输出{iterator.Current}");
            //        result = await iterator.MoveNextAsync();
            //    }

            //    //while (await iterator.MoveNextAsync())
            //    //{
            //    //    Console.WriteLine($"输出{iterator.Current}");
            //    //} 
            #endregion
            Console.WriteLine("GetAsync---结束。。。。");
        }

        /// <summary>
        /// 迭代器--异步
        /// </summary>
        /// <returns></returns>
        static async IAsyncEnumerator<string> GetEnumeratorAsyncFor()
        {
            for (int i = 0; i < 10; i++)
            {
                //await Task.Delay(1000);
                //yield return i.ToString();

                await Task.Delay(1000).ContinueWith((_) =>
                {
                    Console.WriteLine($"迭代器--异步--{i}");
                });
                yield return i.ToString();
            }
            Console.WriteLine("GetEnumeratorAsync---结束。。。。");
        }

        /// <summary>
        /// 迭代器--异步
        /// </summary>
        /// <returns></returns>
        static async IAsyncEnumerator<string> GetEnumeratorAsync()
        {
            await Task.Delay(1000);
            //Console.WriteLine("输出A");
            yield return "B";
            await Task.Delay(1000);
            //Console.WriteLine("输出A");
            yield return "C";
            await Task.Delay(1000);
            //Console.WriteLine("输出A");
            yield return "D";
            Console.WriteLine("GetEnumeratorAsync---结束。。。。");
        }

        /// <summary>
        /// 迭代器
        /// </summary>
        /// <returns></returns>
        static IEnumerator<string> GetEnumerator()
        {
            yield return "A";
            //Console.WriteLine("输出A");
            yield return "B";
            //Console.WriteLine("输出A");
            yield return "C";
            //Console.WriteLine("输出A");
            yield return "D";
            Console.WriteLine("结束。。。。");
        }

        /// <summary>
        /// 测试并发字典ConcurrentDictionary
        /// </summary>
        static void TestConcurrentDictionary()
        {
            #region MyRegion
            ConcurrentDictionary<int, int> cd = new ConcurrentDictionary<int, int>();
            Parallel.For(1, 100, i =>
            {
                cd.AddOrUpdate(1, 1, (key, oldValue) => oldValue + 1);
            });
            Console.WriteLine("After 10000 AddOrUpdates, cd[1] = {0}, should be 10000", cd[1]);
            // Should return 100, as key 2 is not yet in the dictionary
            int value = cd.GetOrAdd(2, (key) => 100);
            Console.WriteLine("After initial GetOrAdd, cd[2] = {0} (should be 100)", value);

            // Should return 100, as key 2 is already set to that value
            value = cd.GetOrAdd(2, 10000);
            Console.WriteLine("After second GetOrAdd, cd[2] = {0} (should be 100)", value);
            //Console.WriteLine("After initial GetOrAdd, cd[2] = {0} (should be 100)", value);
            #endregion
        }
        #endregion
    }
}