Asp.net,cookie, write cookies, take cookies

A cookie is a piece of text information in which the client store Cookie is one of the methods that the session state of ASP. NET will request to associate with session. Cookies can also be used directly to persist data between requests, but the data is then stored on the client and sent to the server along with each request. The browser has a limit on the size of the Cookie, so it is guaranteed to be accepted only if it is not more than 4096 bytes.

Writing cookies

Mode 1:
response.cookies["username"].value= "Mike";
response.cookies["username"]. Expires=datetime.maxvalue;

Mode 2:
HttpCookie acookie = new HttpCookie ("last");
Acookie. Value= "a";
Acookie. Expires=datetime.maxvalue;
RESPONSE.COOKIES.ADD (Acookie);

The notation of multi-valued cookies

Mode 1:
response.cookies["Userinfo1" ["Name"].value= "Mike";
response.cookies["Userinfo1" ["Last"].value= "a";
response.cookies["Userinfo1"]. Expires=datetime.maxvalue;

Mode 2:
HttpCookie cookie = new HttpCookie ("Userinfo1");
Cookies. values["Name"]= "Mike";
Cookies. values["Last"]= "a";
Cookies. Expires=datetime.maxvalue;
Cookies. Expires = System.DateTime.Now.AddDays (1);//Set Expiration time 1 days
RESPONSE.COOKIES.ADD (cookie);




Read cookies
Internet Explorer saves a site's Cookie in a file with a filename format of <user>@<domain>.txt, where <user> is your account name.
Note: Before you obtain the value of a cookie, you should ensure that the cookie does exist. Otherwise, you will get an exception



If (request.cookies["UserName"]!=null)
{
String str = request.cookies ("UserName"). Value;
}

Read a multi-valued cookie
If (request.cookies["UserInfo1"]!=null)
{
String name=request.cookies["UserInfo1" ["Name"];
String last=request.cookies["UserInfo1" ["Last"];
}


Read the Cookie Collection
for (int i = 0; i<request.cookies.count; i++)
{
HttpCookie cookies = request.cookies;
Response.Write ("Name=" +cookies. Mame+ "<br/>");
if (cookies. HasKeys)//Whether there are sub-keys
{
System.Collections.Specialized.NameValueCollection Namecoll
= Acookie.values;
for (int j=0;j<namecoll.count;j++)
{
Response.Write ("sub-key name =" + Namecoll.allkey[j] + "<br/>");
Response.Write ("sub-key value =" + Namecoll[j] + "<br/>");
}

}
Else
{
Response.Write ("Value=" +cookies. Value+ "<br/>");
}
}

When you run this code, you see a cookie,asp named "Asp.net_sessionid". NET uses this Cookie to hold a unique identifier for your session.

Modify Cookies
The method of modification is the same as the creation method

Delete Cookies
Set its validity period to a date in the past. This expired cookie is deleted when the browser checks the validity period of the cookie.



HttpCookie cookie = new HttpCookie ("Userinfo1");
Cookies. Expires=datetime.now.adddays (-30);
RESPONSE.COOKIES.ADD (cookie);


Modify Cookies
1 response.cookies["Info" ["user"] = "2";
2 response.cookies["Info"].        Expires = DateTime.Now.AddDays (1); Delete a property under a cookie
1 HttpCookie acookie=request.cookies["Info"];
2 Acookie. Values.remove ("userid");
3 Acookie. Expires = DateTime.Now.AddDays (1);
4 Response.Cookies.Add (Acookie); Delete all cookies, that is, set the expiration time for now.
1 int limit=request.cookies.count-1;
2 for (int i=0;i<limit;i++)
3 {
4 Acookie = Request.Cookies (i)
5 Acookie. Expires = DateTime.Now.AddDays (-1)
6 Response.Cookies.Add (Acookie)
7}

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If you have a master station and a level two domain name station and the cookie is shared, add the following settings

Cookies. Domain = ". primary domain";
Cookies. Path = "/";

Asp.net,cookie, write a cookie, take a cookie