C#-WebForm-ajax状态保持 （补充）

context.Response.Cookies["Username"].Value = "";

Response.Write(Request.Cookies["Username"].value);

using System;
using System.Web;
using System.Web.SessionState;//第一步：引用命名空间

//第二步：实现接口
public class Login : IHttpHandler, IRequiresSessionState 
{

    public void ProcessRequest(HttpContext context)
    {
        string un = context.Request["uname"];
        string pwd = context.Request["pwd"];

        string json = "{\"ok\":\"0\"}";

        Users u = new UsersData().Select(un, pwd);
        if (u != null)
        {
            context.Session["user"] = un;//第三步：实现Session赋值
            json = "{\"ok\":\"1\"}";
        }
...

Response.Write(Session["user"]);