ASP.NET Cookies
- by Aamir Hasan
Cookies are domain specific and cannot be used across different network domains. The only domain that can read a cookie is the domain that sets it. It does not matter what domain name you set.Cookies are used to store small pieces of information on a client machine. A cookie can store only up to 4 KB of information. Generally cookies are used to store data which user types frequently such as user id and password to login to a site.The HttpCookie class defined in the System.Web namespace represents a browser cookie.Creating cookies (C#)Dim cookie As HttpCookie = New HttpCookie("UID")cookie.Value = "id"cookie.Expires = #3/30/2010#Response.Cookies.Add(cookie)cookie = New HttpCookie("username")cookie.Value = "username"cookie.Expires = #3/31/2010#Response.Cookies.Add(cookie)Creating cookies (VB.NET) HttpCookie cookie = Request.Cookies["Preferences"]; if (cookie == null) { cookie = new HttpCookie("Preferences"); } cookie["Name"] = txtName.Text; cookie.Expires = DateTime.Now.AddYears(1); Response.Cookies.Add(cookie);Creating cookies (C#) HttpCookie MyCookie = new HttpCookie("Background"); MyCookie.Value = "value"; Response.Cookies.Add(MyCookie);Reading cookies (VB.NET)Dim cookieCols As New HttpCookieCollectioncookieCols = Request.CookiesDim str As String' Read and add all cookies to the list boxFor Each str In cookieColsListBox1.Items.Add("Value:" Request.Cookies(str).Value)Next Reading cookies (C#) ArrayList colCookies = new ArrayList(); for (int i = 0; i < Request.Cookies.Count; i++) colCookies.Add(Request.Cookies[i]); grdCookies.DataSource = colCookies; grdCookies.DataBind();Deleting cookies (VB.NET)Dim cookieCols As New HttpCookieCollectioncookieCols = Request.CookiesDim str As String' Read and add all cookies to the list boxRequest.Cookies.Remove("PASS")Request.Cookies.Remove("UID")Deleting cookies (C#)string[] cookies = Request.Cookies.AllKeys; foreach (string cookie in cookies) { ListBox1.Items.Add("Deleting " + cookie); Response.Cookies[cookie].Expires = DateTime.Now.AddDays(-1); }
