当他访问我们的网站时，如何将串行密钥添加到客户系统中

Question

我想使用HTTPCookie访问我的网站时，我想在客户端系统中添加3个串行密钥

但

串行键不同不同。

当我添加第四个cookie时，会自动删除1个键。

我如何做到这一点。

当用户想查看时，他可以看到最近的3个密钥。

您知道如何通过ASP.NET MVC网站将此cookie添加到客户端系统。

我如何将key1，key 2，key3添加到客户端系统。

Answer 1

这是您可以做到的。

写串行键。

//create a cookie
HttpCookie SerialKeys = new HttpCookie("SerialKeys");

//Add serial-key-values in the cookie
SerialKeys.Values.Add("key1", "your-first-serialkey");
SerialKeys.Values.Add("key2", "your-second-serialkey");
SerialKeys.Values.Add("key3", "your-third-serialkey");
SerialKeys.Values.Add("key4", "your-fourth-serialkey");

//set cookie expiry date-time. Made it to last for next 12 hours.
SerialKeys.Expires = DateTime.Now.AddHours(12);

//Most important, write the cookie to client.
Response.Cookies.Add(SerialKeys);

阅读串行键曲奇。

//Assuming user comes back after several hours. several < 12.
//Read the cookie from Request.
HttpCookie SerialKeys = Request.Cookies["SerialKeys"];
if (SerialKeys == null)
{
    //No cookie found or cookie expired.
    //Handle the situation here, Redirect the user or simply return;
}

//ok - cookie is found.
//Gracefully check if the cookie has the key-value as expected.
if (!string.IsNullOrEmpty(SerialKeys.Values["key1"]))
{
    string serialKey = SerialKeys.Values["key1"].ToString();
    //Yes key1 is found. Mission accomplished.
}

if (!string.IsNullOrEmpty(SerialKeys.Values["key2"]))
{
    string serialKey = SerialKeys.Values["key2"].ToString();
    //Yes key2 is found. Mission accomplished.
}

Answer 2

您可以在用户开始会话时向用户添加cookie。这可以通过处理会话开始即使在应用程序的global.asax文件中启动来完成，从而在创建这些键的逻辑代码中添加。

void Session_OnStart() {
    HttpCookie key1 = new HttpCookie("key1","123");   
    Request.Cookies.Add(key1);
}

然后，对于您所谈论的第四个cookie，您可以通过使用使用用户cookie来创建代码逻辑 Response.Cookies["cookie"] 或使用一个使用 Request.Cookies.Remove("cookie");

Answer 3

所有浏览器以一种或另一种方式限制某个网站可以存储的cookie量。例如，如果您的浏览器接受N cookie，则当您发送n+1时，浏览器将删除最旧的cookie。在我看来，这就是正在发生的事情。

一种可能的解决方案是将一个带有各种子视价的cookie而不是单个子值。这样一来，您就可以在一个cookie中拥有尽可能多的值（始终受到cookie最大尺寸限制，即4086字节）。

这样做的代码将是类似的：

//This code creates the cookie, ads some subvalues to it and then adds it to the request so its sent to the browser
HttpCookie cookie = new HttpCookie();
cookie.Name = "MyKeys";            
cookie.Values.Add("Key1", "ValueKey1");
cookie.Values.Add("Key2", "ValueKey2");
cookie.Values.Add("Key3", "ValueKey3");
//etc...

Request.Cookies.Add(cookie);

//This code reads the data from the cookie.
HttpCookie rcookie = Response.Cookies.Get("MyKeys");
string value1, value2, value3;
//We verify it the variable is null because the cookie might not exist in the users browser. If so, this variable would be null
if (rcookie != null) 
{
    value1 = rcookie.Values.Get("Key1");
    value2 = rcookie.Values.Get("Key2");
    value3 = rcookie.Values.Get("Key3");
}