AspNetCore2身份验证

1、在Startup类的Configure方法，添加身份验证的中间件AuthenticationMiddleware

 app.UseAuthentication();

2、在Startup类的ConfigureServices方法，添加Cookie验证的服务，使用Cookies验证体系，

CookieAuthenticationDefaults.AuthenticationScheme="Cookies"

  services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
                .AddCookie(CookieAuthenticationDefaults.AuthenticationScheme, options =>
                {
                    options.AccessDeniedPath = "/Sys/Home/Index";
                    options.LoginPath = "/Sys/Home/Login";
                    options.Cookie.Name = "AuthCookie";
                    options.Cookie.Path = "/";
                    options.Cookie.Expiration = TimeSpan.FromMinutes(30);
                });

3、添加登录action，ClaimsIdentity(string authenticationType)的authenticationType必须和service设置的验证体系一样，才能正常验证，

 [HttpPost]
        [AllowAnonymous]
        public async Task<ActionResult> Login()
        {
            string AdminAccount = Request.Form["AdminAccount"];
            string Password = Request.Form["Password"];
            if (string.IsNullOrWhiteSpace(AdminAccount))
            {
                return JsonError("账号不能为空");
            }
            if (string.IsNullOrWhiteSpace(Password))
            {
                return JsonError("密码不能为空");
            }
            Admin admin = _context.Admins.FirstOrDefault(c => c.AdminAccount == AdminAccount && c.Password == Password);
            if (admin == null)
            {
                return JsonError("用户名或者密码错误");
            }
            ClaimsIdentity identity = new ClaimsIdentity(CookieAuthenticationDefaults.AuthenticationScheme);
            identity.AddClaim(new Claim(ClaimTypes.Name, admin.Id.ToString()));
            await HttpContext.SignInAsync(new ClaimsPrincipal(identity));
            return JsonSuccess();
        }

4、在需要验证的控制器上加[AuthorizeAttribute]特性，通过HttpContext.User.Identity.IsAuthenticated可判断用户是否已通过验证

5、退出登录Action

 /// <summary>
        /// 退出登录
        /// </summary>
        /// <returns></returns>
        public async Task<ActionResult> SignOut()
        {
            await HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
            return JsonSuccess();
        }