销毁C＃/ ASP.NET中的静态变量

Question

I am forced to use static variables because of the asp.net execution path. I have to have the same variables on the master page as well as the page being called. Static variables make it very easy to carry over variables because they remain static. Unfortunately these variables hang in the ether of memory because the app hasn't actually "exited". Is there a way to destroy these variables when I finished used them? I looked into

IDisposable

but its implementation is not... clean. Is there a way to destroy variables when the page finishes rendering?

Answer 1

I am forced to use static variables because of the asp.net execution path. I have to have the same variables on the master page as well as the page being called. Static variables make it very easy to carry over variables because they remain static.

You aren't "forced" to use static fields just to share data between a master page and its content page. You probably don't want to either: static fields will be shared between all requests from all users of your application, which means they need to be thread-safe and limited to data that is shared between all users.

There are many techniques to share data between master and content page. For example, you could use the HttpContext.Items dictionary, which exists only for the duration of a single request.

Answer 2

For anyone looking for a way to "pretend" static variables, here is how you can go about it:

public static Datatype data
{
    get
    {
        return (Datatype)HttpContext.Current.Items["DATA"];
    }
    set
    {
        HttpContext.Current.Items["DATA"] = value;
    }
}

As far as I understand this doesn't necessary solve the "kill static" values, but it should avoid any data collisions caused by static variables. I had my entire project referencing the static variable and changing it would of created more messy code than should be seen. This way, when the call goes out to get "DATA" from your static object, it doesn't grab whatever pointed at but rather uses the context list which gets killed after and is unique to your session.

Answer 3

You can set them to null . If you're using ASP.Net WebForms you can do this inside the Page.Unload event handler.

Answer 4

您应该避免在母版页中使用静态属性，而应使用Session [“”]变量，因为这些变量将在用户结束会话时被销毁。

Answer 5

Without knowing your setup, and thinking in a future of cloud environment as well, where you can have more than one server answering user requests and, you have no idea if the same server will answer all the requests of that user or the load balancer ask the other servers to continue, I would, as I currently do, give you 2 options

Before the options, in a Web Environment, it is good pratice to stop using Sessions or Static variables (for the reason above)

Use cookies

Why not use a cookie to pass value from one place to the other and when consumed, simply write the expiration data back one year and the cookie is gone!

Use MemCached

I always have a Cache layer between my application and the database, and it's the best way to keep values, not only from the database to provide to all users, but a good way to keep variables when we need cross application.

MemCached is free and runs fine on windows, plus there are several Cloud Services that offer this in their servers