详解用Redis实现Session功能

 <appSettings> 
  <!--每台Redis之间用,分割.第一个必须为主机-->
  <add key="SessionRedis" value="127.0.0.1:6384,127.0.0.1:6384"/> 
 </appSettings>

static Managers()
    {
      string sessionRedis= ConfigurationManager.AppSettings["SessionRedis"];
      string timeOut = ConfigurationManager.AppSettings["SessionRedisTimeOut"];

      if (string.IsNullOrEmpty(sessionRedis))
      {
        throw new Exception("web.config 缺少配置SessionRedis,每台Redis之间用,分割.第一个必须为主机");
      }

      if (string.IsNullOrEmpty(timeOut)==false)
      {
        TimeOut = Convert.ToInt32(timeOut);
      }

      var host = sessionRedis.Split(char.Parse(","));
      var writeHost = new string[] { host[0] };
      var readHosts = host.Skip(1).ToArray();

      ClientManagers = new PooledRedisClientManager(writeHost, readHosts, new RedisClientManagerConfig
      {
        MaxWritePoolSize = writeReadCount,//“写”链接池链接数
        MaxReadPoolSize = writeReadCount,//“读”链接池链接数
        AutoStart = true
      });
    }

 /// <summary>
    /// 写入
    /// </summary>
    /// <typeparam name="F"></typeparam>
    /// <param name="doWrite"></param>
    /// <returns></returns>
    public F TryRedisWrite<F>(Func<IRedisClient, F> doWrite)
    {
      PooledRedisClientManager prcm = new Managers().GetClientManagers();
      IRedisClient client = null;
      try
      {
        using (client = prcm.GetClient())
        {
          return doWrite(client);
        }
      }
      catch (RedisException)
      {
        throw new Exception("Redis写入异常.Host:" + client.Host + ",Port:" + client.Port);
      }
      finally
      {
        if (client != null)
        {
          client.Dispose();
        }
      }
    }

   /// <summary>
    /// 以Key/Value的形式存储对象到缓存中
    /// </summary>
    /// <typeparam name="T">对象类别</typeparam>
    /// <param name="value">要写入的集合</param>
    public void KSet(Dictionary<string, T> value)
    {
      Func<IRedisClient, bool> fun = (IRedisClient client) =>
      {
        client.SetAll<T>(value);
        return true;
      };

      TryRedisWrite(fun);
    }

  /// <summary>
  /// 用户状态管理
  /// </summary>
  public class Session
  {
    /// <summary>
    /// 初始化
    /// </summary>
    /// <param name="_context"></param>
    public Session(HttpContextBase _context)
    {
      var context = _context;
      var cookie = context.Request.Cookies.Get(SessionName);
      if (cookie == null || string.IsNullOrEmpty(cookie.Value))
      {
        SessionId = NewGuid();
        context.Response.Cookies.Add(new HttpCookie(SessionName, SessionId));
        context.Request.Cookies.Add(new HttpCookie(SessionName, SessionId));
      }
      else
      {
        SessionId = cookie.Value;
      }
    }

  }

    /// <summary>
    /// 获取当前用户信息
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public object Get<T>() where T:class,new()
    {
      return new RedisClient<T>().KGet(SessionId);
    }

    /// <summary>
    /// 用户是否在线
    /// </summary>
    /// <returns></returns>
    public bool IsLogin()
    {
      return new RedisClient<object>().KIsExist(SessionId);
    }

    /// <summary>
    /// 登录
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="obj"></param>
    public void Login<T>(T obj) where T : class,new()
    {
      new RedisClient<T>().KSet(SessionId, obj, new TimeSpan(0, Managers.TimeOut, 0));
    }
 

    /// <summary>
    /// 延期
    /// </summary>
    /// <param name="key"></param>
    /// <param name="expiresTime"></param>
    public void KSetEntryIn(string key, TimeSpan expiresTime)
    {
      Func<IRedisClient, bool> fun = (IRedisClient client) =>
      {
        client.ExpireEntryIn(key, expiresTime);
        return false;
      };

      TryRedisWrite(fun);
    }

 封装以后
/// <summary>
/// 续期
/// </summary>
public void Postpone()
{
new RedisClient<object>().KSetEntryIn(SessionId, new TimeSpan(0, Managers.TimeOut, 0));
}

namespace Test
{
  public class SessionFilterAttribute : ActionFilterAttribute
  {
    /// <summary>
    /// 每次请求都续期
    /// </summary>
    /// <param name="filterContext"></param>
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
      new Session(filterContext.HttpContext).Postpone();
    }
  }
}

public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
      filters.Add(new SessionFilterAttribute());
    }

    protected void Application_Start()
    {
      RegisterGlobalFilters(GlobalFilters.Filters);
    } 

public static class ExtSessions
{public static Session SessionExt(this Controller controller)
  {
    return new Session(controller.HttpContext);
  }
}

  public class HomeController : Controller
  {
    public ActionResult Index()
    {
      this.SessionExt().IsLogin();
      return View();
    }
  }