MVC 在不使用 RAMMFAR 的情况下为带有文件扩展名的 url 捕获 404 错误

Question

I've done a bit of research into HttpHandlers and HttpModules and I'm not clear on the best way to implement this to my specifications.

My issue is that the StaticFile handler handles all urls with extensions and will return a default IIS 404 page instead of visiting the NotFound action of my ErrorsController . I want to use MVC to handle all 404s because of the benefits of using .cshtml pages over .html pages along with the fact that I perform logging and of all 404 responses and the pages contain some dynamic content.

I don't want to enable <modules runAllManagedModulesForAllRequests="true"> because of the performance impact it causes and because it seems like the wrong way to do this.

Is it plausible to create an HttpModule and have it check for the existence of the requested file and, if not found, send the request to the managed pipeline and eventually to my ErrorsController to handle the request?

Answer 1

My solution here handles all 404s from unauthenticated users, this includes all urls with file extensions. The nice thing about this solution is existingResponse='Auto' determines if a 404 is already handled by the ErrorController and if so it will skip this step but if not, use the provided custom error page.

You will have to skip IIS Custom errors with Response.TrySkipIisCustomErrors = true; .

You might have to set the status code again in the method using Response.StatusCode = (int)HttpStatusCode.NotFound;

In your ErrorController

 [HttpGet]
        public ActionResult 404()
        {
            Response.StatusCode = (int)HttpStatusCode.NotFound;
            Response.TrySkipIisCustomErrors = true;
            return View("Index", new ErrorModel
            {
//Fill in properties values you have in your ErrorModel.
         
            });
        }

In your webconfig .

  <httpErrors errorMode="Custom" existingResponse="Auto">
      <remove statusCode="404" />
      <error statusCode="404" path="/Error/404" responseMode="ExecuteURL" />
    </httpErrors>