ASP.NET Core Interview Question #93

What is status code pages middleware?

Middleware & Request Pipeline Mid-Level Intermediate

Quick Interview Answer

Status code pages middleware can generate simple responses for HTTP error status codes that otherwise have no response body, such as 404 or 403 responses.

Detailed Explanation

Status code pages middleware can generate simple responses for HTTP error status codes that otherwise have no response body, such as 404 or 403 responses.

UseStatusCodePages() is useful for basic responses, while UseStatusCodePagesWithReExecute() can re-execute the pipeline using an error endpoint. MVC applications can then display a user-friendly error page.

It does not replace exception handling middleware because an unhandled exception and an ordinary error status code are different situations.

Code Example

app.UseStatusCodePagesWithReExecute(
    "/Error/{0}");

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");