asp.net 中cookie怎么用，
我想让一个文本框的内容在刷新后不变， 按照网上的建议我试用cookie ， 如下， 但是会报一个错， System.Web.HttpResponse不包含cookie定义， 是不是缺少引用，？？
Response.Cookie("username").value="aa"
username=Request.Cookies("username").value

   public static void SetCookie()
        {
            string CookieName = username; //car name
            int CarCookieExpires = 30; //Expires
            Response.Cookies.Add(new HttpCookie(CookieName,"aa"));
            Response.Cookies[CookieName].Expires = DateTime.Now.AddDays(CarCookieExpires); //保存1月
        } 
 

[解决办法]

引用:

引用:C# code?1234567 public static void SetCookie(HttpResponseBase Response,string CarValue) { string CookieName = username; //car name ……

你那写的是什么哦，照着这样做没错
[解决办法]
写一个普通类


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

namespace YDSystem.ZXF.Common
{
/// <summary>
///Cookie操作基类
/// </summary>
public abstract class Cookies :System.Web.UI.Page
{
/// <summary>
///获取cookie值
/// </summary>
/// <param name="cookieName">cookie名</param>
public static string GetCookieValue (string cookieName)
{
string cookieVal = String.Empty;
cookieVal = HttpContext.Current.Request.Cookies[cookieName].Value;
return cookieVal;
}

/// <summary>
/// 创建cookie
/// </summary>
/// <param name="cookieName">名字</param>
/// <param name="expirationDays">cookie有效时间(以天计)</param>
/// <param name="value">cookie值</param>
public static void CreateCookie (string cookieName, string value, int? expirationDays)
{
HttpCookie Cookie = new HttpCookie(cookieName, value);
if ( expirationDays.HasValue )
Cookie.Expires = DateTime.Now.AddDays(expirationDays.Value );
HttpContext.Current.Response.Cookies.Add(Cookie);
}

/// <summary>
/// 清除指定cookie
/// </summary>
public static void DeleteCookie (string cookieName)

{
HttpCookie Cookie = HttpContext.Current.Request.Cookies[cookieName];
if (Cookie != null)
{
Cookie.Expires = DateTime.Now.AddDays(-2);
HttpContext.Current.Response.Cookies.Add(Cookie);
}
}

/// <summary>
/// 检查cookie
/// </summary>
public static bool CookieExists(string cookieName)
{
bool exists = false;
HttpCookie cookie = HttpContext.Current.Request.Cookies[cookieName];
if (cookie != null)
exists = true;
return exists;
}

/// <summary>
///获取全部cookie
/// </summary>
public static Dictionary<string, string> GetAllCookies()
{
Dictionary<string, string> cookies = new Dictionary<string, string>();
foreach (string key in HttpContext.Current.Request.Cookies.AllKeys)
{
cookies.Add(key, HttpContext.Current.Request.Cookies[key].Value);
}
return cookies;
}

/// <summary>
///清空cookies
/// </summary>
public static void DeleteAllCookies ()
{
var x = HttpContext.Current.Request.Cookies;
foreach (HttpCookie cook in x)
{
DeleteCookie(cook.Name);

}
}

}
}