防止session失效的最佳效果

　　很多时候用到Session都比较厌烦，主要还因为很容易就丢失了！
　　解决的方法有：
　　1、设置Session时间；
　　在Global.ascx文件中的设置时间： Session.Timeout = 600;

　　2、放在服务器里：
　　web.config中配置 <sessionstate mode="stateServer">后，在服务中启动 asp.net state service (asp.net状态服务)
　　除了以上两种方法外，就是Session + Cookies ！双重保险。废话不多说，直接看代码就知道了：

用户登录实例

   
     

    
      
    
      public
    
       
    
      static
    
       
    
      bool
    
       Islogin(
    
      string
    
       Uname, 
    
      string
    
       Pwd, 
    
      bool
    
       writecookie)
{
 
    
      bool
    
       brt 
    
      =
    
       
    
      false
    
      ;
 com.csfqw.passport.API wsLogin 
    
      =
    
       
    
      new
    
       NT.Data.SqlServer.com.csfqw.passport.API();
 DataSet ds 
    
      =
    
       wsLogin.IsLogin(Uname, Pwd);

 
    
      if
    
       (ds.Tables[
    
      0
    
      ].Rows.Count 
    
      >
    
       
    
      0
    
      )
 {
 DataRow dr 
    
      =
    
       ds.Tables[
    
      0
    
      ].Rows[
    
      0
    
      ];
 System.Web.HttpContext.Current.Session[
    
      "
    
      username
    
      "
    
      ] 
    
      =
    
       dr[
    
      "
    
      username
    
      "
    
      ].ToString();
 brt 
    
      =
    
       
    
      true
    
      ;
 
    
      if
    
       (writecookie)
 {
 NTCookies cookie 
    
      =
    
       
    
      new
    
       NTCookies(
    
      "
    
      NetUser
    
      "
    
      );
 cookie.WriteCookie(
    
      "
    
      username
    
      "
    
      , Uname);
 cookie.SetExpires(
    
      60
    
      );
 cookie.Domain 
    
      =
    
       
    
      "
    
      csfqw.com
    
      "
    
      ;
 cookie.RespnseCookies();
 brt 
    
      =
    
       
    
      true
    
      ;
 }
 }
 
    
      return
    
       brt;
}
   
     

 

用户退出实例

   
     

    
      
    
      public
    
       
    
      static
    
       
    
      void
    
       UserLoginOut()
{
 
    
      //
    
      NTCookies cookie = new NTCookies("NetUser");
 
    
      //
    
      cookie.ClearCookies();
 
    
      //
    
      HttpContext.Current.Session.Remove("username");
    
      

    
      
 
    
      ///
    
      退出用户
    
      

    
       HttpCookie cookie 
    
      =
    
      System.Web.HttpContext.Current.Request.Cookies[
    
      "
    
      NetUser
    
      "
    
      ];
 
    
      if
    
       (cookie 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       cookie[
    
      "
    
      username
    
      "
    
      ] 
    
      !=
    
       
    
      null
    
      )
 {
 cookie.Expires 
    
      =
    
       DateTime.Now.AddDays(
    
      -
    
      1.0d
    
      );
 cookie.Domain 
    
      =
    
       
    
      "
    
      csfqw.com
    
      "
    
      ;
 System.Web.HttpContext.Current.Response.AppendCookie(cookie);
 }

 
    
      ///
    
      撤销专家
    
      

    
       HttpCookie expertcookie 
    
      =
    
       System.Web.HttpContext.Current.Request.Cookies[
    
      "
    
      IsExpert
    
      "
    
      ];
 
    
      if
    
       (expertcookie 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       expertcookie[
    
      "
    
      Expert
    
      "
    
      ] 
    
      !=
    
       
    
      null
    
      )
 {
 expertcookie.Expires 
    
      =
    
       DateTime.Now.AddDays(
    
      -
    
      1.0d
    
      );
 expertcookie.Domain 
    
      =
    
       
    
      "
    
      csfqw.com
    
      "
    
      ;
 System.Web.HttpContext.Current.Response.AppendCookie(expertcookie);
 }
 HttpContext.Current.Session.Remove(
    
      "
    
      username
    
      "
    
      );
 HttpContext.Current.Session.Remove(
    
      "
    
      Expert
    
      "
    
      );
}