.Net中cookie的使用

COOKIE是一段文本信息,在客户端存储 COOKIE 是 ASP.NET 的会话状态将请求与会话关联的方法之一。COOKIE 也可以直接用于在请求之间保持数据&＃xff0c;但数据随后将存储在客户端并随每个请求一起发送到服务器。浏览器对 COOKIE 的大小有限制&＃xff0c;因此&＃xff0c;只有不超过 4096 字节才能保证被接受。

编写COOKIE

代码

1 //方式1:
2  Response.COOKIEs["username"].value&＃61;"mike";
3 Response.COOKIEs["username"].Expires&＃61;DateTime.MaxValue;
4
5  //方式2:
6 HttpCOOKIE aCOOKIE &＃61; new HttpCOOKIE("last");
7 aCOOKIE.Value&＃61;"a";
8 aCOOKIE..Expires&＃61;DateTime.MaxValue;
9 Response.COOKIEs.Add(aCOOKIE);
10
11 //多值COOKIE的写法
12
13 //方式1:
14 Response.COOKIEs["userinfo1"]["name"].value&＃61;"mike";
15 Response.COOKIEs["userinfo1"]["last"].value&＃61;"a";
16 Response.COOKIEs["userinfo1"].Expires&＃61;DateTime.MaxValue;
17
18 //方式2:
19 HttpCOOKIE COOKIE &＃61; new HttpCOOKIE("userinfo1");
20 COOKIE.Values["name"]&＃61;"mike";
21 COOKIE.Values["last"]&＃61;"a";
22 COOKIE.Expires&＃61;DateTime.MaxValue;
23 //COOKIE.Expires &＃61; System.DateTime.Now.AddDays(1);//设置过期时间 1天
24 Response.COOKIEs.Add(COOKIE);
25
26

运行此代码时&＃xff0c;可看到一个名为“ASP.NET_SessionId”的COOKIE&＃xff0c;ASP.NET用这个 COOKIE 来保存您的会话的唯一标识符。

修改 COOKIE
修改的方法与创建方法相同

代码

修改COOKIE
1 Response.COOKIEs["Info"]["user"] &＃61; "2";
2 Response.COOKIEs["Info"].Expires &＃61; DateTime.Now.AddDays(1); 删除COOKIE下的属性
1 HttpCOOKIE aCOOKIE&＃61;Request.COOKIEs["Info"];
2 aCOOKIE.Values.Remove("userid");
3 aCOOKIE.Expires &＃61; DateTime.Now.AddDays(1);
4 Response.COOKIEs.Add(aCOOKIE); 删除所有COOKIE&＃xff0c;就是设置过期时间为现在就行了
1 int limit&＃61;Request.COOKIEs.Count - 1;
2 for(int i&＃61;0;i<limit;i&＃43;&＃43;)
3 {
4 aCOOKIE &＃61; Request.COOKIEs(i)
5 aCOOKIE.Expires &＃61; DateTime.Now.AddDays(-1)
6 Response.COOKIEs.Add(aCOOKIE)
7 }

删除 COOKIE
将其有效期设置为过去的某个日期。当浏览器检查 COOKIE 的有效期时&＃xff0c;就会删除这个已过期的 COOKIE。

读取COOKIE
Internet Explorer 将站点的 COOKIE 保存在文件名格式为 &＃64;.txt 的文件中&＃xff0c;其中 是您的帐户名。
注意:在获取COOKIE的值之前&＃xff0c;应该确保该 COOKIE 确实存在。否则&＃xff0c;您将得到一个异常

代码

If (Request.COOKIEs["userName"]!&＃61;null)
{
string str &＃61; Request.COOKIEs("userName").Value;
}

//多值COOKIE的读取
If ( Request.COOKIEs["userInfo1"]!&＃61;null )
{
string name&＃61;Request.COOKIEs["userInfo1"]["name"];
string last&＃61;Request.COOKIEs["userInfo1"]["last"];
}


//读取 COOKIE 集合
for(int i &＃61; 0 ;i<Request.COOKIEs.Count ;i&＃43;&＃43;)
{
HttpCOOKIE COOKIEs &＃61; Request.COOKIEs;
Response.Write("name&＃61;"&＃43;COOKIEs.Mame&＃43;"
");
if (COOKIEs.HasKeys )//是否有子键
{
System.Collections.Specialized.NameValueCollection NameColl
&＃61; aCOOKIE.Values ;
for(int j&＃61;0;j<NameColl.Count;j&＃43;&＃43;)
{
Response.Write("子键名&＃61;"&＃43; NameColl.AllKey[j] &＃43;"
");
Response.Write("子键值&＃61;"&＃43; NameColl[j] &＃43;"
");
}

}
else
{
Response.Write("value&＃61;"&＃43;COOKIEs.Value&＃43;"
");
}
}

代码

//----------写入COOKIE
HttpCOOKIE COOKIE &＃61; new HttpCOOKIE("userinfo1");
COOKIE.Expires &＃61; System.DateTime.Now.AddMinutes(2);//设置过期时间
for (int i &＃61; 0; i < 20; i&＃43;&＃43;)
{

COOKIE.Values["Val" &＃43;i.ToString()] &＃61; i.ToString();
Response.COOKIEs.Add(COOKIE);
}

//读取 COOKIE 集合
for (int i &＃61; 0; i < Request.COOKIEs.Count; i&＃43;&＃43;)
{
if (Request.COOKIEs.AllKeys[i] &＃61;&＃61; "userinfo1")
{

HttpCOOKIE COOKIEs &＃61; Request.COOKIEs["userInfo1"];
Response.Write("name&＃61;" &＃43; COOKIEs.Name &＃43; "
");
//Response.Write("name&＃61;" &＃43; COOKIEs.Value &＃43; "
");

if (COOKIEs.HasKeys)//是否有子键
{
System.Collections.Specialized.NameValueCollection NameColl &＃61; COOKIEs.Values;
for (int j &＃61; 0; j < NameColl.Count; j&＃43;&＃43;)
{
Response.Write("子键名&＃61;" &＃43; NameColl.AllKeys[j] &＃43; "
");
Response.Write("子键值&＃61;" &＃43; NameColl[j] &＃43; "
");
}

}
else
{
Response.Write("value&＃61;" &＃43; COOKIEs.Value &＃43; "
");
}
}

}

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