\API::error(function (\Illuminate\Validation\ValidationException $exception){
  $data =$exception->validator->getMessageBag();
   $msg = collect($data)->first();
   if(is_array($msg)){
     $msg = $msg[0];
   }
   return response()->json(['message'=>$msg,'status_code'=>400], 200);
 });
 \API::error(function (\Dingo\Api\Exception\ValidationHttpException $exception){
   $errors = $exception->getErrors();
   return response()->json(['message'=>$errors->first(),'status_code'=>400], 200);
 });

public function render($request, Exception $exception)
  {
    if($exception instanceof \Illuminate\Validation\ValidationException){
      $data = $exception->validator->getMessageBag();
      $msg = collect($data)->first();
      if(is_array($msg)){
        $msg = $msg[0];
      }
      return response()->json(['message'=>$msg],200);
    }

    if (in_array('api',$exception->guards())){
      if($exception instanceof AuthenticationException){
        return response()->json(['message'=>'token错误'],200);
      }
      if($exception instanceof ModelNotFoundException){
        return response()->json(['message'=>'该模型未找到'],200);
      }

    }

    return parent::render($request, $exception);
  }