c# - How to assign model validation error to a key -

in same way can add model validation within controller:

modelstate.addvalidationerror([key], "this error message") 

can add error within model validation using annotations?

// demonstration purposes [required(errormessage = "this error message"), adderrormessagetokey = [key]] public string username { get; set; } 

sometimes it's not appropriate add error message particular property. in application wish show 1 error message.

you can put helper every property in viewpage .

@html.validationmessage("customerror") 

and in controller:

use tempdata in actionresult    tempdata["customerror"] = "this error message";