Question

我在使用HttpContext类时遇到了麻烦。我可以访问HttpContext但不能调用它的函数。

我想在我写的助手类中使用HttpContext.Authentication。

我不能在我的帮助类中写下这样的内容（见下文）：

var ageText = "32f"
var age = Double(ageText)
then do..
print(age!)

但是，我可以在我的控制器类中访问HttpContext。

我很感激任何帮助。提前谢谢。

Answer 1

首先创建文件HttpContext.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

namespace System.Web
{
    public static class HttpContext
    {
        private static IHttpContextAccessor _contextAccessor;

        public static Microsoft.AspNetCore.Http.HttpContext Current => _contextAccessor.HttpContext;

        internal static void Configure(IHttpContextAccessor contextAccessor)
        {
            _contextAccessor = contextAccessor;
        }
    }

    public static class StaticHttpContextExtensions
    {
        public static void AddHttpContextAccessor(this IServiceCollection services)
        {
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
        }

        public static IApplicationBuilder UseStaticHttpContext(this IApplicationBuilder app)
        {
            var httpContextAccessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();
            System.Web.HttpContext.Configure(httpContextAccessor);
            return app;
        }
    }
}

启动文件中的下一步

public void ConfigureServices(IServiceCollection services)
...
 services.AddTransient<IHttpContextAccessor, HttpContextAccessor>();
 services.AddHttpContextAccessor();
...

最后，例如，在控制器之外，如果您需要当前用户名

var currentUsername = !string.IsNullOrEmpty(System.Web.HttpContext.Current?.User?.Identity?.Name)
            ? System.Web.HttpContext.Current.User.Identity.Name
            : "Anonymous";

我测试了ASPNET Core 1.0和1.1

EDIT 对不起，我在你的启动文件中忘了配置添加这个：

public void Configure(IApplicationBuilder app)
...
app.UseStaticHttpContext();
...

Answer 2

如果你想使用一个登录用户的帮助程序类，你应该改为使用扩展方法，它可以包裹IHttpContextAccessor或HttpContext本身。

public static class HttpContextExtensions 
{
    public static void SignInUser(this HttpContext context)
    {
        await context.Authentication.SignInAsync(..);
    }

    public static void SignInUser(this.IHttpContextAccessor contextAccessor) 
    {
        // Calls the method from above
        contextAccessor.HttpContext.SignInUser();
    }
}

或者，如果您有更大的依赖关系链并需要其他注入服务，请将其转换为可注入类：

public class UserLogonService : IUserLogonService 
{
    private readonly IHttpContextAccessor contextAccessor;

    public UserLogonService(IHttpContextAccessor contextAccessor)
    {
        if(contextAccessor==null)
            throw new ArgumentNullException(nameof(contextAccessor));

        this.contextAccessor = contextAccessor;
    }

    public void SingInUser()
    {
        contextAccessor.HttpContext.SignInUser();
    }
}

并在Startup.Configure方法中：

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddSingleton<IUserLogonService, UserLogonService>();

现在，您可以通过构造函数在项目的任何位置注入IUserLogonService，即

public class MyController
{
    private readonly IUserLogonService userLogon;

    public MyController(IUserLoggonService userLogon)
    {
        this.userLogon = userLogon;
    }

    public async Task<IActionResult> Login()
    {
        await userLogon.SignInUser();
    }
}

它干净，分离，可以很容易地进行单元测试，而静态助手类无法做到这一点。

你如何使用'HttpContext'类？

2 个答案: