Quản lý trạng thái với ASP.NET

ViewState["RequestCount"] = count;

int count = (int)ViewState[nRequestCount"];

[Serializable] 
public class Book { ... }

protected void Page_Load(object sender, EventArgs e)
{
if(Page.IsPostBack==false)
{
Book book = new Book(1, "Harry Potter”); 
ViewState[MmyBookM] = book;
}
}

protected void Button1_Click(object sender, EventArgs e) {
Book book = (Book)ViewState["myBook"]; 
Labell.Text = book.ID + " " + book.BookName;
} 

Response.Cookies[cookie][(key)|.attribute] = value;

value = Request.Cookies[cookie][(key)|.attribute]

Response.Cookies["userName"].Value = "DOTNET";
Response.Cookies["userName"].Expires = DateTime.Now.AddDays(1);

if (Request.Cookies["userName"] != null)
LabelUsername.Text = Request.Cookies["userName"].Value;

Response.Cookies["userName"].Expires=DateTime.Now.AddDays(-1); 

Response.Cookies["userInfo"]["userName"] = "DOTNET";
Response.Cookies["userInfo"]["lastVisit"]=DateTime.Now.ToString(); 
Response.Cookies["userInfo"].Expires = DateTime.Now.AddDays(1);

if (Request.Cookies["userInfo"] != null) {
LabelUsername.Text = Request.Cookies["userInfo"]["userName"]; 
LabelLastVisit.Text = Request.Cookies["userInfo"]["lastVisit"];
}

Response.Cookies["userInfo"].Expires = DateTime.Now.AddDays(-1);

HttpCookie cookie = new HttpCookie("userInfo"); 
cookie["userName"] = "DOTNET";
cookie["lastVisit"] = DateTime.Now.ToString(); 
cookie.Expires = DateTime.Now.AddDays(1); Response.Cookies.Add(cookie);

HttpCookie cookie = Request.Cookies["userInfo"]; 
if (cookie != null) {
LabelUsername.Text = cookie["userName"]; 
LabelLastVisit.Text = cookie["lastVisit"];
}

Session["name"] = value;

Object obj = (Object)Session["name"];

Session.Timeout = minutes;

//global.asax
<script language="C#" runat="server">
void Session_OnStart(Object sender, EventArgs E) {
Session["IsLogin"] = 0;
}
</script> 

//Login.aspx.cs
void btnLogin_Click(Object Src, EventArgs E) {
if ([Thong tin dang nhap dung]) 
Session ["IsLogin"] = 1;
else
Response.Write("Vui lòng nhập lại!");
}

//MyForm.aspx.cs
void Page_Load(Object Src, EventArgs E){ 
int nDaDangNhap = (Int32) Session ["IsLogin"];
if (nDaDangNhap == 0)
Response.Redirect("Login.aspx");
}

//MyForm.aspx.cs 
void btnLogout_Click(Object Src, EventArgs E){ 
Session ["IsLogin"]  = 0;
Response.Redirect("Login.aspx");
}

Application["SiteRequestCount”] = 0; 
Application["SiteName"] = "www.dotnet.vn";

int count = (int)Application["SiteRequestCount"]; 
string name = (string)Application["SiteName"];

Application.Lock();
if (Application["SiteRequestCount"] == null)
{
Application["SiteRequestCount"] = 0;
}
count = (int)Application[nSiteRequestCount"]; 
count++;
Application[nSiteRequestCount"] = count; 
Application.UnLock(); 

<%@ Application Language="C#" %>
<script runat="server">
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup Application["SiteRequestCount"] = 0; 
Application["SiteName"] = "www.dotnet.vn";
}
</script> 

//global.asax
<script language="C#" runat="server">
void Application_OnStart(Object sender, EventArgs E) { 
Application["SoLan"] = 0;
}
</script>
//Myform.aspx.cs
void Page_Load(Object Src, EventArgs E){
Application.Lock() ;
Application["SoLanf'] = (Int32) Application ["SoLan"] + 1; 
Application.UnLock() ;
Response.Write("Số lần vào trang này :" + Application["SoLan"]);
}

public static string GetCart(HttpContext context)
{
ShoppingCart cart = (ShoppingCart)context.Session["Cart"];
// Handle missing cart
..
// Output the cart item markup for this session to a string
string output = "";
foreach (CartItem item in cart)
{
output += "<p class='cartRow'>";
output += item.Name + "</p>";
}
return output;
}

Book b = new Book(1, "Harry Potter");
Cache["book”] = b;

Cache.Insert("Book", b, null, Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(2)); // expire sau 2 phút kể từ lần truy cập cuối
Cache.Insert("Book", b, null, DateTime.Now.AddMinutes(2.0), Cache.NoSlidingExpiration); // expire trong vòng 2 phút