有没有一种方法可以只为ASP.NET Core 2.2 MVC中的SignalR集线器设置CORS策略？

Question

I have an ASP.NET Core 2.2 MVC project and I need to set CORS policy specifically for SignalR hub but not globally (not for all controllers and actions). If I follow recommendations by adding app.UseCors() it works but globally and I need to apply the policy only for SignalR. Is there a way to do that?

I have tried this too but with no success.

EDIT 2019-07-22 18:33 CEST

Here is CORS policy I use:

services.AddCors(o =>
            {
                o.AddPolicy("MyCorsPolicy", b =>
                {
                    b.AllowAnyHeader()
                    .AllowAnyMethod()
                    .SetIsOriginAllowed(s => true)
                    .AllowCredentials();
                });
            });

Answer 1

After hours of attempts I had to turn to GitHub and this is what Brennan Conroy suggested: https://github.com/aspnet/AspNetCore/issues/12564

And it works!

Edit 2019-07-29 13:40 CEST

This is what helped:

app.Map("/path", c =>
{
    c.UseCors("somePolicy");
    c.UseSignalR(route =>
    {
        route.MapHub<MyHub>("/hub");
    });
});

And clients will connect to the hub via "/path/hub".