Handle validation failures myself in ASP.NET MVC

Question

We all know that familiar ASP.NET error page that we see many times during development. To keep a consistent feel to my site, I\'d rather the user not see those errors, and hand

Answer 1

Request validation is not the same as model validation. Request validation (which you can disable using [ValidateInput(false)]) tries to protect potentially dangerous user input from ever reaching your controller / action method. This is why the exception is thrown from the request pipeline before the input ever reaches your controller.

I don't think you can change this pipeline behavior without forking the MVC WebRuntime source code and using your own personal branch of the MVC library. You shouldn't do that.

However, you can probably handle the error and redirect to a custom error page by using Application_Error in your global.asax.

var ex = Server.GetLastError();
if (ex == null) return;
if (ex.GetType() == typeof(HttpException) && ex.Message.StartsWith(
    "A potentially dangerous Request.Path value was detected from the client"))
    // redirect to your custom error page here

Answer 2

Create a single base controller. Add [ValidateInput(false)] to the controller class:

 [ValidateInput(false)]
 public class BaseController : Controller
 {

 }

And then update every controller to inherit from it:

 public class HomeController : BaseController
 {

 }

I don't suggest turning off Request Validation myself but if you must, you can.