Feb1613
Creating a NotFound / 404 rule within ASP.NET Core is quite simple, and once you've created that you'll be able to create custom error pages for all error status codes.
- 1. Update the Startup.cs Located at the root of any ASP.NET Core application is the Startup.cs file containing all the necessary bootstrap code.
- 2. Update the Configure method with the following:
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
...
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseBrowserLink();
}
else
{
//redirects all errors given their error code
app.UseStatusCodePagesWithReExecute("/error/{0}");
app.UseApplicationInsightsExceptionTelemetry();
}
...
}The above code will now redirect all errors, e.g. a 404 not found error will get redirected to /error/404. Now we need to setup the routes and controllers to handle these requests.
- 3. Update the routing rules
We now need a routing rule to handle all the potential error redirects.
Update the routing rules with the following:
...
//This routes specifically handles 404 not found requests
routes.MapRoute(
name: "Error-404-Route",
template: "error/404",
defaults: new { controller = "Error", action = "NotFound" }
);
routes.MapRoute(
name: "Error-StatusCode-Route",
template: "error/{statusCode}",
defaults: new { controller = "Error", action = "InternalServerError" }
);
...- 4. Create an error controller
Create an error controller in a new file ErrorController.cs with the following code, making sure you take any areas into account if applicable
using Microsoft.AspNetCore.Mvc;
namespace Test.Controllers
{
public class ErrorController : Controller
{
public IActionResult InternalServerError(int statusCode)
{
...
return View("~/Views/Error/500.cshtml");
}
public IActionResult NotFound()
{
...
return View("~/Views/Error/404.cshtml");
}
}
}- 5. Create the associated views
Now we need to create error views for the associated errors, i.e. ~/Views/Error/404.cshtml
<div>404 Not Found<div/>