fix

app/index/service/Cart.php

@@ -70,7 +70,7 @@ class Cart extends BaseService
         $model = new CartModel;
         $carts = $model->where('user_id', '=', $userId)
             ->where('is_delete', '=', 0)
-            ->select();
+            ->select()->toArray();
         return array_column($carts,'id');
     }