I have an issue with ASP.NET Core Web API, where I want to display a custom error message model if non of the controller actions were matched.
So, it would be a 404 error but with a customized body.
I haven't tried anything because I am not sure if this is even possible.
You can add a catch-all route by adding an action method with a route that will always match if no other does.
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
routes.MapRoute(
name: "CatchAll",
template: "{*url}",
defaults: new { controller = "CatchAll", action = "Index" });
});
For Web API:
public class CatchAllController : Controller
{
[HttpGet("{*url}", Order = int.MaxValue)]
public IActionResult Index()
{
return NotFound(YourModel)
}
}
For MVC:
public class CatchAllController : Controller
{
public IActionResult Index()
{
Response.StatusCode = StatusCodes.Status404NotFound;
return View();
}
}
app.UseExceptionHandler(errorApp =>
{
errorApp.Run(async context =>
{
context.Response.StatusCode = 500;
});
});
Using this middleware you can actually catch the code and then handle it accordingly. It's taken from this page . There are various other examples in the link some simpler ones might fit you better
