1 public class LoginCheckAttribute: ActionFilterAttribute
 2 {
 3 　　public override void OnActionExecuting(ActionExecutingContext filterContext) 
 4 　　{
 5     　　// 判斷是否檢查登陸
 6     　　var noNeedCheck = false;
 7     　　string msg = filterContext.HttpContext.Request.Path;
 8 
 9     　　if (filterContext.ActionDescriptor is ControllerActionDescriptor controllerActionDescriptor)
10     　　{
11     　　　　noNeedCheck = controllerActionDescriptor.MethodInfo.GetCustomAttributes(inherit: true)
12                       .Any(a => a.GetType().Equals(typeof(NoNeedLoginAttribute)));
13     　　}
14     　　if (noNeedCheck) return;
15 
16     　　bool isLogin = filterContext.HttpContext.Session.GetString("_Name") !=null?true:false;//你的驗證是否登錄方法
17     　　if (!isLogin)
18     　　{
19     　　　　filterContext.HttpContext.Response.Redirect("/Account/Login", true);//跳轉登錄頁面
20     　　}
21 
22     　　base.OnActionExecuting(filterContext);
23     }
24 }

1 public class NoNeedLoginAttribute: ActionFilterAttribute
2 {
3 　　public override void OnActionExecuting(ActionExecutingContext filterContext)
4    {
5 　　　　base.OnActionExecuting(filterContext);
6 
7 　　}
8 }

1 public void ConfigureServices(IServiceCollection services)
2 {
3 　　//全局過濾器
4    services.AddMvc(config => config.Filters.Add(new LoginCheckAttribute()));
5 }

1 public class AccountController : Controller
2 {
3     [NoNeedLogin]
4      public IActionResult Login()
5      {
6          return View();
7      }        
8 }

 1 public class LoginCheckAttribute: ActionFilterAttribute
 2     {
 3         public bool IsChecked { get; set; }
 4         public override void OnActionExecuting(ActionExecutingContext filterContext) 
 5         {
 6             
 7             if (IsChecked) 
 8             {
 9                 bool isLogin = filterContext.HpptContext.Session.GetString("_Name")!=null? true:false;//你的驗證是否登錄方法
10                 if (!isLogin)
11                 {
12                     filterContext.HttpContext.Response.Redirect("/Account/Login", false);
13                 }
14             }
15 
16             base.OnActionExecuting(filterContext);
17         }
18     }
19 
20 
21 //Startup.cs頁面添加配置
22 public void ConfigureServices(IServiceCollection services)
23 {
24 　　//全局過濾器
25    services.AddMvc(config => config.Filters.Add(new LoginCheckAttribute(){IsChecked = true}));
26 }
27 
28 
29 //控制器
30 //1.該控制器不需要驗證登錄
31 [LoginCheck(IsChecked = false)]
32 public class AccountController : Controller
33 {
34     public IActionResult Login()
35     {
36         return View();
37     }        
38 }
39 
40 
41 //2.該控制器需要驗證是否登錄
42 public class UserController : Controller
43 {
44     public IActionResult Index()
45     {
46         return View();
47     }        
48 }