ASP.NET Cookies简单应用 [ASP.NET | Cookies]

 

前言

          一般只要有会员、用户机制的网站或论坛在登录的时候都会有这么一个复选框——[记住我的名字 | 两周内不再登陆 | 在此计算机上保存我的信息]，说法较多，实现起来差不多，本文做了一个简单的例子并附带了一个C# Cookies帮助类 CookiesHelper.cs和实现代码片段，希望能对初学者有帮助: )

 

推荐文章

          1.     林信良 index.dat文件剖析  较深入分析cookies在index.dat中存入情况

          2.     MSDN —— ASP.NET Cookie 概述 很全面很详细的介绍了Cookies

 

正文

          CookiesHelper.cs

using  System;
using  System.Collections.Generic;
using  System.Text;
using  System.Web;

namespace  TLibrary.ObjectHelper
{
     public   class  CookiesHelper
    {

         #region  获取Cookie

         ///   <summary>
         ///  获得Cookie的值
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <returns></returns>
         public   static   string  GetCookieValue( string  cookieName)
        {
             return  GetCookieValue(cookieName,  null );
        }

         ///   <summary>
         ///  获得Cookie的值
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         ///   <returns></returns>
         public   static   string  GetCookieValue( string  cookieName, string  key)
        {
            HttpRequest request  =  HttpContext.Current.Request;
             if  (request  !=   null )
                 return  GetCookieValue(request.Cookies[cookieName], key);
             return   "" ;
        }

         ///   <summary>
         ///  获得Cookie的子键值
         ///   </summary>
         ///   <param name="cookie"></param>
         ///   <param name="key"></param>
         ///   <returns></returns>
         public   static   string  GetCookieValue(HttpCookie cookie,  string  key)
        {
             if  (cookie  !=   null )
            {
                 if  ( ! string .IsNullOrEmpty(key)  &&  cookie.HasKeys)
                     return  cookie.Values[key];
                 else
                     return  cookie.Value;
            }
             return   "" ;
        }

         ///   <summary>
         ///  获得Cookie
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <returns></returns>
         public   static  HttpCookie GetCookie( string  cookieName)
        {
            HttpRequest request  =  HttpContext.Current.Request;
             if  (request  !=   null )
                 return  request.Cookies[cookieName];
             return   null ;
        }

         #endregion

         #region  删除Cookie

         ///   <summary>
         ///  删除Cookie
         ///   </summary>
         ///   <param name="cookieName"></param>
         public   static   void  RemoveCookie( string  cookieName)
        {
            RemoveCookie(cookieName, null );
        }

         ///   <summary>
         ///  删除Cookie的子键
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         public   static   void  RemoveCookie( string  cookieName, string  key)
        {
            HttpResponse response  =  HttpContext.Current.Response;
             if  (response  !=   null )
            {
                HttpCookie cookie  =  response.Cookies[cookieName];
                 if  (cookie  !=   null )
                {
                     if  ( ! string .IsNullOrEmpty(key)  &&  cookie.HasKeys)
                        cookie.Values.Remove(key);
                     else
                        response.Cookies.Remove(cookieName);
                }
            }
        }

         #endregion

         #region  设置/修改Cookie

         ///   <summary>
         ///  设置Cookie子键的值
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         public   static   void  SetCookie( string  cookieName,  string  key,  string  value)
        {
            SetCookie(cookieName, key, value,  null );
        }

         ///   <summary>
         ///  设置Cookie值
         ///   </summary>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         public   static   void  SetCookie( string  key,  string  value)
        {
            SetCookie(key,  null , value,  null );
        }

         ///   <summary>
         ///  设置Cookie值和过期时间
         ///   </summary>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         ///   <param name="expires"></param>
         public   static   void  SetCookie( string  key,  string  value, DateTime expires)
        {
            SetCookie(key,  null , value, expires);
        }

         ///   <summary>
         ///  设置Cookie过期时间
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="expires"></param>
         public   static   void  SetCookie( string  cookieName, DateTime expires)
        {
            SetCookie(cookieName,  null ,  null , expires);
        }

         ///   <summary>
         ///  设置Cookie
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         ///   <param name="expires"></param>
         public   static   void  SetCookie( string  cookieName,  string  key,  string  value, DateTime ?  expires)
        {
            HttpResponse response  =  HttpContext.Current.Response;
             if  (response  !=   null )
            {
                HttpCookie cookie  =  response.Cookies[cookieName];
                 if  (cookie  !=   null )
                {
                     if  ( ! string .IsNullOrEmpty(key)  &&  cookie.HasKeys)
                        cookie.Values.Set(key, value);
                     else
                         if  ( ! string .IsNullOrEmpty(value))
                            cookie.Value  =  value;
                     if  (expires  !=   null )
                        cookie.Expires  =  expires.Value;
                    response.SetCookie(cookie);
                }
            }
            
        }

         #endregion

         #region  添加Cookie

         ///   <summary>
         ///  添加Cookie
         ///   </summary>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         public   static   void  AddCookie( string  key,  string  value)
        {
            AddCookie( new  HttpCookie(key, value));
        }

         ///   <summary>
         ///  添加Cookie
         ///   </summary>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         ///   <param name="expires"></param>
         public   static   void  AddCookie( string  key,  string  value, DateTime expires)
        {
            HttpCookie cookie  =   new  HttpCookie(key, value);
            cookie.Expires  =  expires;
            AddCookie(cookie);
        }

         ///   <summary>
         ///  添加为Cookie.Values集合
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         public   static   void  AddCookie( string  cookieName, string  key,  string  value)
        {
            HttpCookie cookie  =   new  HttpCookie(cookieName);
            cookie.Values.Add(key, value);
            AddCookie(cookie);
        }

         ///   <summary>
         ///  添加为Cookie集合
         ///   </summary>
         ///   <param name="cookieName"> Cookie名称 </param>
         ///   <param name="expires"> 过期时间 </param>
         public   static   void  AddCookie( string  cookieName, DateTime expires)
        {
            HttpCookie cookie  =   new  HttpCookie(cookieName);
            cookie.Expires  =  expires;
            AddCookie(cookie);
        }

         ///   <summary>
         ///  添加为Cookie.Values集合
         ///   </summary>
         ///   <param name="cookieName"></param>
         ///   <param name="key"></param>
         ///   <param name="value"></param>
         ///   <param name="expires"></param>
         public   static   void  AddCookie( string  cookieName,  string  key,  string  value, DateTime expires)
        {
            HttpCookie cookie  =   new  HttpCookie(cookieName);
            cookie.Expires  =  expires;
            cookie.Values.Add(key, value);
            AddCookie(cookie);
        }

         ///   <summary>
         ///  添加Cookie
         ///   </summary>
         ///   <param name="cookie"></param>
         public   static   void  AddCookie(HttpCookie cookie)
        {
            HttpResponse response  =  HttpContext.Current.Response;
             if  (response  !=   null )
            {
                 // 指定客户端脚本是否可以访问[默认为false]
                cookie.HttpOnly  =   true ;         
                 // 指定统一的Path，比便能通存通取
                cookie.Path  =   " / " ;
                 // 设置跨域,这样在其它二级域名下就都可以访问到了
                 // cookie.Domain = "chinesecoo.com";
                response.AppendCookie(cookie);
            }
        }

         #endregion
    }
}

代码注意事项:

          1.     Cookies添加的时候注意一个Cookie可以添加多个子键

          2.     假如你不显示的设置   HttpCookie.Expires   那么此   cookie   生命期即为浏览器进程——关闭浏览器则过期

          3.     需要了解HttpCookie.Domain和HttpCookie.Path这两个属性，对于跨域和存储路径等高级应用有帮助

 

以下看实际调用代码

          页面加载

     protected   void  Page_Load( object  sender, EventArgs e)
    {
         if  ( ! IsPostBack)
        {
            HttpCookie Cookie  =  CookiesHelper.GetCookie( " UserInfo " );
             if  (Cookie  !=   null )
            {
                 this .txtUserName.Value  =  Cookie.Values[ " uName " ];
            }
        }
    }

          代码说明：

                    1.     this.txtUserName是界面上输入用户名的控件，换成自己的控件名称就行；

                    2.     UserInfo为Cookie的名称，uName为Cookie的子键。

          这段代码的功能是在页面加载的时候显示用户Cookie中记录的用户名，这里也可以做成连密码一起记录然后在这里显示，这样用户就可以直接点登录按钮了

 

          登录验证

         string  uName  =   this .txtUserName.Value.Trim();

         // 验证用户名密码
         if  (IsLogin(uName,  this .txtPass.Value.Trim()))
        {
             // 记住我的名字
             if  ( ! string .IsNullOrEmpty(Request[ " remUsername " ]))
            {
                HttpCookie Cookie  =  CookiesHelper.GetCookie( " UserInfo " );
                 if  (Cookie  ==   null )
                {
                    Cookie  =   new  HttpCookie( " UserInfo " );
                    Cookie.Values.Add( " uName " , uName);
                     // 设置Cookie过期时间
                    Cookie.Expires  =  DateTime.Now.AddDays( 365 );
                    CookiesHelper.AddCookie(Cookie);
                }
                 else   if  ( ! Cookie.Values[ " uName " ].Equals(uName))
                    CookiesHelper.SetCookie( " UserInfo " ,  " uName " , uName);
            }
            Response.Redirect( " ~/index.aspx " );
        }

          代码说明：

                    1.     this.txtUserName和this.txtPass是界面上输入用户名和密码的控件，换成自己的控件名称就行；

                    2.     IsLogin方法是用来验证用户名和密码是否正确的，这里替换成自己的验证方法就行了。

                    3.     Request["remUsername"]是获得界面上是否选中了[记住我的名称]复选框

          这段代码的功能是在用户登录成功之后，如果选中了记住登录用户名就把用户名存入客户端的Cookie中，并设置过期时间为1年。

 

补充 

               1.     根据实际的经验，一般的情况下在本地调试不设置Domain属性，挂上服务器上配上域名之后就得指定Domain参数了，否则Cookies出不来的。（2008-11-24 10:32:00）            

 

结束

          发这文的时候犹豫了一下，说实在的查下MSDN基本上就搞定了，但是从别人的字典里到自己的字典里还是不一样的，学习开心，多多翻下MSDN  :)