I noticed in ASP.NET Core MVC ModelStateInvalidFilter checks if Context.Result == null before checking ModelState.IsValid? What's the reason?

CodePudding user response：

The answer in the Result property description comment in the ActionExecutingContext.cs:

Gets or sets the IActionResult to execute. Setting Result to a non-null value inside an action filter will short-circuit the action and any remaining action filters.

This means if the short-circuit of the action already initiated there is no reason to overwrite the previous value in case the context.ModelState.IsValid set to false. It would be wrong approach.