深入学习Cookie

public sealed class HttpCookie
{
    // 获取或设置将此 Cookie 与其关联的域。默认值为当前域。
    public string Domain { get; set; }
    // 获取或设置此 Cookie 的过期日期和时间（在客户端）。
    public DateTime Expires { get; set; }
    // 获取一个值，通过该值指示 Cookie 是否具有子键。
    public bool HasKeys { get; }
    // 获取或设置一个值，该值指定 Cookie 是否可通过客户端脚本访问。
    // 如果 Cookie 具有 HttpOnly 属性且不能通过客户端脚本访问，则为 true；否则为 false。默认为 false。
    public bool HttpOnly { get; set; }
    // 获取或设置 Cookie 的名称。
    public string Name { get; set; }
    // 获取或设置要与当前 Cookie 一起传输的虚拟路径。默认值为当前请求的路径。
    public string Path { get; set; }
    // 获取或设置一个值，该值指示是否使用安全套接字层 (SSL)（即仅通过 HTTPS）传输 Cookie。
    public bool Secure { get; set; }
    // 获取或设置单个 Cookie 值。默认值为空引用。
    public string Value { get; set; }
    // 获取单个 Cookie 对象所包含的键值对的集合。
    public NameValueCollection Values { get; }
    // 获取 System.Web.HttpCookie.Values 属性的快捷方式。
    public string this[string key] { get; set; }
}

HttpCookie cookie = new HttpCookie("MyCookieName", "string value");
Response.Cookies.Add(cookie);

HttpCookie cookie = Request.Cookies["MyCookieName"];
if( cookie != null )
    labCookie1.Text = cookie.Value;
else
    labCookie1.Text = "未定义";

HttpCookie cookie = new HttpCookie("MyCookieName", null);
cookie.Expires = new DateTime(1900, 1, 1);
Response.Cookies.Add(cookie);

public class DisplaySettings
{
    public int Style;

    public int Size;
   
    public override string ToString()
    {
        return string.Format("Style = {0}, Size = {1}", this.Style, this.Size);
    }   
}

private void WriteCookie_2a()
{
    DisplaySettings setting = new DisplaySettings { Style = 1, Size = 24 };

    HttpCookie cookie = new HttpCookie("DisplaySettings1");
    cookie["Style"] = setting.Style.ToString();
    cookie["Size"] = setting.Size.ToString();

    Response.Cookies.Add(cookie);
}

private void ReadCookie_2a()
{
    HttpCookie cookie = Request.Cookies["DisplaySettings1"];
    if( cookie == null )
        labDisplaySettings1.Text = "未定义";
    else {
        DisplaySettings setting = new DisplaySettings();
        setting.Style = cookie["Style"].TryToInt();
        setting.Size = cookie["Size"].TryToInt();
        labDisplaySettings1.Text = setting.ToString();
    }
}

private void WriteCookie_2b()
{
    DisplaySettings setting = new DisplaySettings { Style = 2, Size = 48 };

    HttpCookie cookie = new HttpCookie("DisplaySettings2", setting.ToJson());
    Response.Cookies.Add(cookie);
}

private void ReadCookie_2b()
{
    HttpCookie cookie = Request.Cookies["DisplaySettings2"];
    if( cookie == null )
        labDisplaySettings2.Text = "未定义";
    else {
        DisplaySettings setting = cookie.Value.FromJson<DisplaySettings>();
        labDisplaySettings2.Text = setting.ToString();
    }
}

/// <summary>
/// 将一个对象序列化成 JSON 格式字符串
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
public static string ToJson(this object obj)
{
    if( obj == null )
        return string.Empty;

    javascriptSerializer jss = new JavaScriptSerializer();
    return jss.Serialize(obj);
}

/// <summary>
/// 从JSON字符串中反序列化对象
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="cookie"></param>
/// <returns></returns>
public static T FromJson<T>(this string cookie)
{
    if( string.IsNullOrEmpty(cookie) )
        return default(T);

    JavaScriptSerializer jss = new JavaScriptSerializer();
    return jss.Deserialize<T>(cookie);
}

<input type="button" onclick="WriteCookie();" value="WriteCookie" />
<script type="text/javascript">
    function WriteCookie() {
        var cookie = "cookie_js=22222222; path=/";
        document.cookie = cookie;
    }   
</script>

<input type="button" onclick="ReadCookie();" value="ReadCookie" />
<script type="text/javascript">
    function ReadCookie() {
        alert(document.cookie);
    }   
</script>

/**
 * Create a cookie with the given name and value and other optional parameters.
 *
 * @example $.cookie('the_cookie', 'the_value');
 * @desc Set the value of a cookie.
 * @example $.cookie('the_cookie', 'the_value', {expires: 7, path: '/', domain: 'jquery.com', secure: true});
 * @desc Create a cookie with all available options.
 * @example $.cookie('the_cookie', 'the_value');
 * @desc Create a session cookie.
 * @example $.cookie('the_cookie', null);
 * @desc Delete a cookie by passing null as value.
 *
 * @param String name The name of the cookie.
 * @param String value The value of the cookie.
 * @param Object options An object literal containing key/value pairs to provide optional cookie attributes.
 * @option Number|Date expires Either an integer specifying the expiration date from now on in days or a Date object.
 *                             If a negative value is specified (e.g. a date in the past), the cookie will be deleted.
 *                             If set to null or omitted, the cookie will be a session cookie and will not be retained
 *                             when the the browser exits.
 * @option String path The value of the path atribute of the cookie (default: path of page that created the cookie).
 * @option String domain The value of the domain attribute of the cookie (default: domain of page that created the cookie).
 * @option Boolean secure If true, the secure attribute of the cookie will be set and the cookie transmission will
 *                        require a secure protocol (like HTTPS).
 * @type undefined
 *
 * @name $.cookie
 * @cat Plugins/Cookie
 * @author Klaus Hartl/klaus.hartl@stilbuero.de
 */

/**
 * Get the value of a cookie with the given name.
 *
 * @example $.cookie('the_cookie');
 * @desc Get the value of a cookie.
 *
 * @param String name The name of the cookie.
 * @return The value of the cookie.
 * @type String
 *
 * @name $.cookie
 * @cat Plugins/Cookie
 * @author Klaus Hartl/klaus.hartl@stilbuero.de
 */
jQuery.cookie = function(name, value, options) {
    if (typeof value != 'undefined') { // name and value given, set cookie
        options = options || {};
        if (value === null) {
            value = '';
            options.expires = -1;
        }
        var expires = '';
        if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) {
            var date;
            if (typeof options.expires == 'number') {
                date = new Date();
                date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000));
            } else {
                date = options.expires;
            }
            expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE
        }
        var path = options.path ? '; path=' + options.path : '';
        var domain = options.domain ? '; domain=' + options.domain : '';
        var secure = options.secure ? '; secure' : '';
        document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');
    } else { // only name given, get cookie
        var cookieValue = null;
        if (document.cookie && document.cookie != '') {
            var cookies = document.cookie.split(';');
            for (var i = 0; i < cookies.length; i++) {
                var cookie = jQuery.trim(cookies[i]);
                // Does this cookie string begin with the name we want?
                if (cookie.substring(0, name.length + 1) == (name + '=')) {
                    cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                    break;
                }
            }
        }
        return cookieValue;
    }
};

<sessionState mode="InProc" cookieName="ASP.NET_SessionId" cookieless="UseCookies"></sessionState>

Session["Key1"] = DateTime.Now;

<sessionState cookieName="SK"></sessionState>