在Handler里面使用Session

using System.Web;
using System;
using System.Web.SessionState;//需要引用

/// <summary>
/// MyHandler 的摘要说明
/// </summary>
public class MyHandler : IHttpHandler, IReadOnlySessionState //需要实现IReadOnlySessionState接口
{
    public MyHandler() { }
    public void ProcessRequest(HttpContext context) 
    {
        context.Response.Write(context.Session["aa"]);
    }
    public bool IsReusable
    {
        get { return false; }
    }

}