标签助手是使用 net core 3.1 LTS 的错误路由链接

Question

I use ASP.NET Core 3.1 LTS and route setting like this

app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id?}");

                endpoints.MapControllerRoute(
                    name: "Backend",
                    pattern: "{area:exists}/{controller=Home}/{action=Index}");

                 endpoints.MapRazorPages();
            });

and my areas razor page have a tag helper

<a class="btn btn-primary btn-sm" asp-area="Backend" asp-controller="Article" asp-action="Create"> Create</a>

usually this link will be /backend/article/create

but result is /article/create?area=backend

why result is wrong ?

Answer 1

1. The registering order of routes matters.

   \napp.UseEndpoints(endpoints => \n{ \n     \n    endpoints.MapControllerRoute( \n        name: "Backend", \n        pattern: "{area:exists}/{controller=Home}/{action=Index}");\n    endpoints.MapControllerRoute( \n        name: "default",\n        pattern: "{controller=Home}/{action=Index}/{id?}");\n     endpoints.MapRazorPages();\n}); \n

2. Make sure the area of Backend exists. Otherwise, it will be treated as querystring. For example, if you have already had an Area of Backend (Need to use the standard Area Folder Structure + Namespace , and annotate the controller with [Area("Backend")] , see official docs )

    [Area("Backend")] // important public class ArticleController : Controller { public IActionResult Create(){ ...}

   then the following code

   <a asp-area="Backend" asp-controller="Article" asp-action="Create"> Create</a> <a asp-area="AnAreaThatDoesnotExist" asp-controller="Article" asp-action="Create"> Create</a>

   will generate routes as below:

    <a href="/Backend/Article/Create"> Create</a> <a href="/Article/Create?area=AnAreaThatDoesnotExist"> Create</a>

   Note we specify an parameter of area=AnAreaThatDoesnotExist which doesn't exist at all and then the area=AnAreaThatDoesnotExist will be used as query string.