ASP.NET Core Filter如何支持依赖注入

通过Filter来支持；分别有IResourceFilter AuthorizeFilter ActionFilter ExceptionFilter ResultFilter，Filter也被称为拦截器

那么 ASP.NET Core Filter如何支持依赖注入?可以通过全局注册，支持依赖注入。通过TypeFilter(typeof(Filter)) 标记在方法，标记在控制器。通过ServiceType(typeof(Filter))标记在方法，标记在控制器，必须要注册Filter这类；TypeFilter和ServiceType的本质是实现了一个IFilterFactory接口；

代码如下

   public class HomeController : Controller
    {
        private readonly ILoggerFactory _loggerFactory;

        public HomeController(ILoggerFactory factory)
        {
            _loggerFactory = factory;
        }

        //[TestActionFilter]
        //  [TypeFilter(typeof(TestActionFilterAttribute))]
        //  [ServiceFilter(typeof(TestActionFilterAttribute))]
        public IActionResult Index()
        {
            return View();
        }

        public IActionResult Privacy()
        {
            return View();
        }

    public class TestActionFilterAttribute : Attribute, IActionFilter
    {
        private readonly ILogger _logger;

        public TestActionFilterAttribute(ILoggerFactory logger)
        {
            _logger = logger.CreateLogger("TestActionFilterAttribute");
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
            _logger.LogDebug($"11111");

            if (context.HttpContext.Request.Query.TryGetValue("id", out StringValues value))
            {
                Console.WriteLine(value.First());
            }
            else
            {
                context.HttpContext.Response.Redirect("/Error/404");
            }
        }

        public void OnActionExecuting(ActionExecutingContext context)
        { }
    }