ASP.NET的Cookie跨域有关问题 _ASP

ASP.NET的Cookie跨域问题

将Cookie的有效范围限制到域。?
默认情况下，Cookie 与特定的域相关联。
例如，如果您的站点是 ? www.contoso.com，那么当用户向该站点请求页面时，
您编写的Cookie就被发送到服务器。（有特定路径值的Cookie除外） ?
如果您的站点有子域（例如 ? contoso.com、sales.contoso.com ? 和 ? support.contoso.com），
就可以把Cookie同特定的子域相关联。为此，需要设置Cookie的 ? Domain ? 属性，如下所示：?

Response.Cookies(?"domain?").Value???=???DateTime.Now.ToString?
Response.Cookies(?"domain?").Expires???=???DateTime.Now.AddDays(1)?
Response.Cookies(?"domain?").Domain???=???"support.contoso.com?"?

如果按照这种方式设置域，则Cookie只能用于指定子域中的页面。?
您也可以利用Domain属性来创建可在多个子域中共享的Cookie。例如，对域进行如下设置：?

Response.Cookies(?"domain?").Value???=???DateTime.Now.ToString?
Response.Cookies(?"domain?").Expires???=???DateTime.Now.AddDays(1)?
Response.Cookies(?"domain?").Domain???=???"contoso.com?"?

这样，该 ? Cookie ? 就可用于主域、sales.contoso.com ? 和 ? support.contoso.com。?

以下是创建一个跨域的Cookie,只能实现同一个根域下的Cookie
如：www.it100.info，在这个根域下的所有二级域名可共享Cookie,{mail.it100.info,photo.it100.info}

?? ? ? ?public?static?bool?CreateCookie(string?strCookieName,?string?strCookieValue,?string?strDomain,?bool?blURLEncode)
????????{
????????????if?(blURLEncode)
????????????{
????????????????strCookieValue?=?System.Web.HttpContext.Current.Server.UrlEncode(strCookieValue);
????????????}
????????????HttpCookie?objCookie?=?new?HttpCookie(strCookieName,?strCookieValue);
????????????objCookie.Domain?=?strDomain;?//设置Cookie的域名
????????????System.Web.HttpContext.Current.Response.Cookies.Add(objCookie);
????????????return?true;
????????}

url:http://greatverve.cnblogs.com/archive/2011/07/05/asp-net-cookie-domain.html

Cookie有三个属性需要注意一下：
1. Domain 域
2. Path?????? 路径
3. Expires 过期时间

跨域操作需要设置域属性:
Response.Cookies("MyCookie").Domain = "cnblogs.com"; (这里指的是泛域名)
这样在其它二级域名下就都可以访问到了， ASP 和 ASP.NET 测试通过

虚拟目录下访问：
我在ASP端做了下测试，.NET的没试, 如果不指定Path属性，不同虚拟目录下Cookie无法共享
将Response.Cookies("MyCookie").Path = "/" 就可以了

总的写法:
Response.Cookies("MyCookie").Domain = "cnblogs.com";
Response.Cookies("MyCookie").Path = "/"
Response.Cookies("MyCookie").Expires = Now + 365;
Response.Cookies("MyCookie")("Test") = "test";

.NET 清除Cookie
HttpCookie cookie = System.Web.HttpContext.Current.Request.Cookies[cookiename];
if (cookie != null)
{
??????????????? cookie.Values.Clear();
??????????????? SetUserCookieExpireTime(cookiename, -1);
??????????????? cookie.Domain = _domain;
??????????????? System.Web.HttpContext.Current.Response.Cookies.Set(cookie);
}
public static void SetUserCookieExpireTime(string key, int days)
{
??????????? System.Web.HttpContext.Current.Response.Cookies[key].Domain = _domain;
??????????? System.Web.HttpContext.Current.Response.Cookies[key].Path = _cookiepath;
??????????? System.Web.HttpContext.Current.Response.Cookies[key].Expires = DateTime.Now.AddDays(days);
}
.NET 添加/更新Cookie
public static void AddUserCookies(string key,string value, string cookiename, string domain)
{
??????????? HttpCookie cookie = System.Web.HttpContext.Current.Request.Cookies[cookiename];
??????????? if (cookie == null)
??????????? {
??????????????? cookie = new HttpCookie(cookiename);
??????????????? cookie.Domain = domain;
??????????????? cookie.Path = _cookiepath;

??????????????? cookie.Values.Add(key, value);
??????????????? HttpContext.Current.Response.AppendCookie(cookie);
??????????? }
??????????? else
??????????? {
??????????????? if (System.Web.HttpContext.Current.Request.Cookies[cookiename].Values[key] != null)
??????????????? {
??????????????????? cookie.Values.Set(key, value);
??????????????? }
??????????????? else
??????????????? {
??????????????????? cookie.Domain = domain;
??????????????????? cookie.Path = _cookiepath;

??????????????????? cookie.Values.Add(key, value);
??????????????????? HttpContext.Current.Response.AppendCookie(cookie);
??????????????? }
??????????? }
}

这种写法实现cookie跨域跨目录