MVC1002: Route attribute cannot be applied to page handler methods

Cause

An attribute implementing IRouteTemplateProvider was applied to a Razor Page handler method.

Rule description

Razor Page handler methods are selected after routing is completed, and consequently cannot contribute a route. Applying a route attribute such as HttpGet or HttpPost to a Razor Page handler is not supported.

public class IndexModel : PageModel
{
    [HttpGet("/my-url")]
    public IActionResult OnGet() => Page();
}

How to fix violations

Remove the route attribute from the handler. Routes can be specified for a Razor Page using an @page directive or by using conventions. For more information, see custom routes in Razor Pages.

When to suppress warnings

Don't suppress warnings from this rule.