Session-JZTXT

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Session;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace ConsoleApp1
{
    public static class Sample02
    {
        public static void Start()
        {
            Host.CreateDefaultBuilder()
                .ConfigureWebHostDefaults(builder => builder
                    .ConfigureServices(collection => collection
                        .AddDistributedMemoryCache()               //基于内存的缓存服务，让Session使用，这里可以换成redis
                        .AddSession())                             //注册Session
                    .Configure(app => app
                        .UseSession()                              //使用Session
                        .Run(ProcessAsync)))                       //运行中间件      
                .Build()
                .Run();

            static async Task ProcessAsync(HttpContext context)      
            {
                var session = context.Session;                   //获得context 的Session
 
                await session.LoadAsync();                       //从缓存中获得  Session的状态               
                string sessionStartTime;

                if (session.TryGetValue("SessionStartTime", out var value))    //后面读取出来
                {
                    sessionStartTime = Encoding.UTF8.GetString(value);         //编码
                }
                else
                {
                    sessionStartTime = DateTime.Now.ToString(CultureInfo.InvariantCulture);
                    session.SetString("SessionStartTime", sessionStartTime);     //第一次设置一个sessionStartTime
                }

                // 使用反射获取Session Key
                var field = typeof(DistributedSession).GetTypeInfo().GetField("_sessionKey", BindingFlags.Instance | BindingFlags.NonPublic);
                var sessionKey = field?.GetValue(session);                    //获得DistributedSession: ISession

                context.Response.ContentType = "text/html";
                await context.Response.WriteAsync($"<html><body><ul><li>Session ID:{session.Id}</li>");   //每次会话的ID，第一次会通过相应头发给客户端，默认20分钟失效（最后一次发的请求），每次刷新都变动
                await context.Response.WriteAsync($"<li>Session Key:{sessionKey}</li>");                  //会话有效期不变，刷新不变，但估计过期后会变动
                await context.Response.WriteAsync($"<li>Session Start Time:{sessionStartTime}</li>");
                await context.Response.WriteAsync($"<li>Current Time:{DateTime.Now}</li></ul></table></body></html>");
            }
        }
    }
}