c# - 如何在静态类中使用 IHttpContextAccessor 设置 cookie

Question

我正在尝试在静态类中创建通用 addReplaceCookie 方法。该方法看起来像这样

public static void addReplaceCookie(string cookieName, string cookieValue)
{

    if ((HttpContext.Current.Request.Cookies(cookieName) == null))
    {
        // add cookie
        HttpCookie s = new HttpCookie(cookieName);
        s.Value = cookieValue;
        s.Expires = DateTime.Now.AddDays(7);
        HttpContext.Current.Response.Cookies.Add(s);
    }
    else {
        // ensure cookie value is correct 
        HttpCookie existingSchoolCookie = HttpContext.Current.Request.Cookies(cookieName);
        existingSchoolCookie.Expires = DateTime.Now.AddDays(7);
        existingSchoolCookie.Value = cookieValue;
        HttpContext.Current.Response.Cookies.Set(existingSchoolCookie);
    }

}

我知道要在 asp.net core 中获取 HttpContext，您必须使用 IHttpContextAccessor。但是我不能将它注入(inject)静态类。

还有其他方法可以访问它吗？

我正在使用 rc1-final。

Answer 1

虽然我建议远离像这样的静态类场景，但仍有可能实现您的要求。

假设一个静态类...

public class MyStaticHelperClass {
    private static IHttpContextAccessor httpContextAccessor;
    public static void SetHttpContextAccessor(IHttpContextAccessor  accessor) {
        httpContextAccessor = accessor;
    }

    public static void addReplaceCookie(string cookieName, string cookieValue) {
        var HttpContext = httpContextAccessor.HttpContext;
        if (HttpContext.Request.Cookies(cookieName) == null) {
            // add cookie
            HttpCookie s = new HttpCookie(cookieName);
            s.Value = cookieValue;
            s.Expires = DateTime.Now.AddDays(7);
            HttpContext.Response.Cookies.Add(s);
        } else {
            // ensure cookie value is correct 
            HttpCookie existingSchoolCookie = HttpContext.Request.Cookies(cookieName);
            existingSchoolCookie.Expires = DateTime.Now.AddDays(7);
            existingSchoolCookie.Value = cookieValue;
            HttpContext.Response.Cookies.Set(existingSchoolCookie);
        }
    }
}

您可以在 Startup.ConfigureServices 中添加访问器，因为它不再自动添加

public void ConfigureServices(IServiceCollection service) {

    //Register IHttpContextAccessor and its implementation.
    services.AddHttpContextAccessor();

    services.AddTransient<IMyService, MyService>();
    services.AddMvc();

    //...
}

并通过注入(inject)Startup.Configure方法获取服务

public void Configure(IApplicationBuilder app, IHostingEnvironment env, IHttpContextAccessor accessor)
{
    MyStaticHelperClass.SetHttpContextAccessor(accessor);

    //...

}

现在完成了。我仍然强烈建议将您的静态类转换为服务，其具体实现将使用 IHttpContextAccessor 作为可以通过其构造函数注入(inject)的依赖项。

public interface ICookieService {
    void AddReplaceCookie(string cookieName, string cookieValue);
}

public class CookieService : ICookieService {
    IHttpContextAccessor httpContextAccessor;
    public CookieService(IHttpContextAccessor httpContextAccessor) {
        this.httpContextAccessor = httpContextAccessor;
    }
    public void AddReplaceCookie(string cookieName, string cookieValue) {
        var HttpContext = httpContextAccessor.HttpContext;
        if (HttpContext.Request.Cookies(cookieName) == null) {
            // add cookie
            HttpCookie s = new HttpCookie(cookieName);
            s.Value = cookieValue;
            s.Expires = DateTime.Now.AddDays(7);
            HttpContext.Response.Cookies.Add(s);
        } else {
            // ensure cookie value is correct 
            HttpCookie existingSchoolCookie = HttpContext.Request.Cookies(cookieName);
            existingSchoolCookie.Expires = DateTime.Now.AddDays(7);
            existingSchoolCookie.Value = cookieValue;
            HttpContext.Response.Cookies.Set(existingSchoolCookie);
        }
    }
}

...然后可以在服务集合中注册...

public void ConfigureServices(IServiceCollection service) {

    services.AddHttpContextAccessor();

    services.AddTransient<ICookieService, CookieService>();
    services.AddMvc();
}

...并且可以注入(inject)到需要它的类中。

public class SomeClassThatNeedCookieServicesController : Controller {
    ICookieService cookieService;

    public SomeClassThatNeedCookieServicesController(ICookieService cookieService) {
        this.cookieService = cookieService;
    }

    //...
}

这就是我在我的应用程序中管理 session cookie 的方式。