ASP.net core 3.1で Web API の Validateを試してみる

core 3.1で
ActionFilterAttributeを使ってみたのですが
ずいぶん変わっているようですね？

using System.Linq ; using Microsoft.AspNetCore.Mvc ; using Microsoft.AspNetCore.Mvc.Filters ; using Microsoft.AspNetCore.Mvc.ModelBinding ; using Microsoft.Extensions.Logging ; namespace FiltersSample.Filters public class ValidateIdAttribute : ActionFilterAttribute // パラメータのnullチェックをするかどうか public string ParameterName { get ; set ; } private readonly ILogger < ValidateIdAttribute > _logger ; public ValidateIdAttribute () _logger = new LoggerFactory (). CreateLogger < ValidateIdAttribute >(); ParameterName = "id" ; public override void OnActionExecuting ( ActionExecutingContext actionContext ) if (! actionContext . ActionArguments . All ( x => x . Key != ParameterName || checkValue ( x . Value as string ?? string . Empty ))) // 数字じゃない string message = $"バリデート: { ParameterName } に数字以外が含まれます。" ; actionContext . ModelState [ ParameterName ]. Errors . Add ( message ); actionContext . ModelState [ ParameterName ]. ValidationState = ModelValidationState . Invalid ; _logger . LogError ( message ); actionContext . Result = new BadRequestObjectResult ( actionContext . ModelState ); //actionContext.Result = new BadRequestResult();// こっちだと既定のbodyが返る else if (! actionContext . ModelState . IsValid ) // Data Annotationsでひっかかった string message = string . Join ( "; " , actionContext . ModelState . Select ( pair => $" { pair . Key } = { pair . Value . RawValue . ToString ()} " )); _logger . LogError ( $"バリデート: { message } " ); actionContext . Result = new BadRequestObjectResult ( actionContext . ModelState ); //actionContext.Result = new BadRequestResult();// こっちだと既定のbodyが返る // その他チェックすべきものがあれば実装 base . OnActionExecuting ( actionContext ); private bool checkValue ( string id ) return id . Length == 12 && id . All ( char . IsDigit ); 呼び出すのは

using FiltersSample.Filters ; using Microsoft.AspNetCore.Mvc ; using Microsoft.Extensions.Logging ; using System.Collections.Generic ; // For more information on enabling Web API for empty projects, visit https://go.microsoft.com/fwlink/?LinkID=397860 namespace FiltersSample.Controllers [ Route ( "api/[controller]" )] [ ApiController ] public class IdController : ControllerBase // GET: api/<IdController> [ HttpGet ] [ ValidateId ( ParameterName = "id" )] public IEnumerable < string > Get ( string id ) return new string [] { "id" , id };

な感じでいいいみたいです

https://localhost:xxxx/api/Id?id=12345678
な感じでリクエストしてみてください

https://dev.azure.com/lowguy/_git/sample?path=%2F3.1sample