ASP.NET Core 好像不能像20年前那样直接使用Session函数，我使用如下方法

1、在NuGet安装以下2个包

2、在Program.cs注册

//注册Session
builder.Services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromMinutes(60);
    options.Cookie.HttpOnly = false;
});
//注册上下文
builder.Services.AddHttpContextAccessor();

var app = builder.Build();

//启用Session
app.UseSession();

3、在控制器中使用

public class HomeController : Controller
{
    private readonly ILogger<HomeController> _logger;

    private readonly ISession _session; //session对象
    private readonly IHttpContextAccessor _contextAccessor; //上下文对象

    //构造函数的参数中引用IHttpContextAccessor对象
    //再把它和它的Session赋值给本控制器的_contextAccessor和_session 
    public HomeController(ILogger<HomeController> logger, IHttpContextAccessor contextAccessor)
    {
        _logger = logger;
        _contextAccessor = contextAccessor; 
        _session = contextAccessor.HttpContext.Session;
    }

    public IActionResult Index()
    {
          //然后可以使用_session来添加或者读取需要的变量
        _session.SetString("uname", "Jack");
        ViewData["uid"] = _session.GetString("uname");
        return View();
    }

}