如何在asp.net中创建持久Cookie?

你可以这样做。

//create a cookie
HttpCookie myCookie = new HttpCookie("myCookie");

//Add key-values in the cookie
myCookie.Values.Add("userid", objUser.id.ToString());

//set cookie expiry date-time. Made it to last for next 12 hours.
myCookie.Expires = DateTime.Now.AddHours(12);

//Most important, write the cookie to client.
Response.Cookies.Add(myCookie);

正在读取持久cookie。

//Assuming user comes back after several hours. several < 12.
//Read the cookie from Request.
HttpCookie myCookie = Request.Cookies["myCookie"];
if (myCookie == null)
{
    //No cookie found or cookie expired.
    //Handle the situation here, Redirect the user or simply return;
}

//ok - cookie is found.
//Gracefully check if the cookie has the key-value as expected.
if (!string.IsNullOrEmpty(myCookie.Values["userid"]))
{
    string userId = myCookie.Values["userid"].ToString();
    //Yes userId is found. Mission accomplished.
}

虽然接受的答案是正确的,但它没有说明原始代码无法工作的原因。

HttpCookie userid = new HttpCookie("userid", objUser.id.ToString());
userid.Expires.AddYears(1);
Response.Cookies.Add(userid);

看看第二行。过期的依据是Expires属性,该属性包含默认值1/1/0001。以上代码的计算结果为1/1/0002。此外,计算结果不会保存回该属性。相反,Expires属性应该以当前日期为基础进行设置。

更正代码:

HttpCookie userid = new HttpCookie("userid", objUser.id.ToString());
userid.Expires = DateTime.Now.AddYears(1);
Response.Cookies.Add(userid);

FWIW在未加密的cookie中存储像userid这样的东西时要非常小心。这样做会使你的网站很容易出现cookie中毒,用户可以很容易地模仿另一个用户。如果您正在考虑这样的事情,我强烈建议您直接使用表单验证cookie。

bool persist = true;

var cookie = FormsAuthentication.GetAuthCookie(loginUser.ContactId, persist);

cookie.Expires = DateTime.Now.AddMonths(3);

var ticket = FormsAuthentication.Decrypt(cookie.Value);

var userData = "store any string values you want inside the ticket
                 extra than user id that will be encrypted"

var newTicket = new FormsAuthenticationTicket(ticket.Version, ticket.Name,
     ticket.IssueDate, ticket.Expiration, ticket.IsPersistent, userData);

cookie.Value = FormsAuthentication.Encrypt(newTicket);

Response.Cookies.Add(cookie);

string userId = null;
if (this.Context.User.Identity.IsAuthenticated) 
{
    userId = this.Context.User.Identity.Name;
}

据我所知,您使用ASP.NET身份验证并要设置cookies持久性,您需要设置FormsAuthenticationTicket.IsPersistent=true

bool isPersisted = true;
var authTicket = new FormsAuthenticationTicket(
1,
user_name, 
DateTime.Now,
DateTime.Now.AddYears(1),//Expiration (you can set it to 1 year)
isPersisted,//THIS IS THE MAIN FLAG
addition_data);
    HttpCookie authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, authTicket );
    if (isPersisted)
        authCookie.Expires = authTicket.Expiration;

HttpContext.Current.Response.Cookies.Add(authCookie);

HttpContext.Current.Response.Cookies.Add(userid);

当您需要读取cookie的值时,可以使用类似以下的方法:

    string cookieUserID= String.Empty;

    try
    {
        if (HttpContext.Current.Request.Cookies["userid"] != null)
        {
            cookieUserID = HttpContext.Current.Request.Cookies["userid"];
        }
    }
    catch (Exception ex)
    {
       //handle error
    }

    return cookieUserID;

//添加cookie

var panelIdCookie = new HttpCookie("panelIdCookie");
panelIdCookie.Values.Add("panelId", panelId.ToString(CultureInfo.InvariantCulture));
panelIdCookie.Expires = DateTime.Now.AddMonths(2); 
Response.Cookies.Add(panelIdCookie);

//读取cookie

    var httpCookie = Request.Cookies["panelIdCookie"];
                if (httpCookie != null)
                {
                    panelId = Convert.ToInt32(httpCookie["panelId"]);
                }