ASP.NET Core MVC如何在Filter中获取ControllerName和ActionName，以及在Action方法上声明的Filter

在ASP.NET Core MVC的Filter中，我们可以通过ActionContext对象获取到许多有用的信息，例如下面的代码在IAuthorizationFilter中，获取了ControllerName和ActionName，以及在Action方法上声明的Filter：

using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Mvc.Filters;

namespace AspNetCoreMVCFilterDescriptor.Filters
{
    public class AuthorizationFilterAttribute : Attribute, IAuthorizationFilter
    {
        public void OnAuthorization(AuthorizationFilterContext context)
        {
            ControllerActionDescriptor? controllerActionDescriptor = context.ActionDescriptor as ControllerActionDescriptor;
            string? controllerName = controllerActionDescriptor?.ControllerName;//获取ControllerName
            string? actionName = controllerActionDescriptor?.ActionName;//获取ActionName

            //获取在Action方法上声明的Filter
            IList<FilterDescriptor>? filters = controllerActionDescriptor?.FilterDescriptors;
            foreach (var filterDescriptor in filters!)
            {
                Type filterType = filterDescriptor.Filter.GetType();
            }
        }
    }
}

甚至我们还可以获取声明Filter的Controller的Action方法参数值，详情查看这里。