Laravel 5.7：自定义验证规则。无法使用注入构造函数的类

使用 Laravel 5.7 自定义验证规则

php
public function boot()
{
    $this->app->bind('customValidator', function ($app) {
        return new CustomValidator(new Dependency());
    });
}

php
Validator::extend('custom_rule', function ($attribute, $value, $parameters, $validator) {
    $customValidator = app('customValidator');
    return $customValidator->validate($value);
});

php
// AppServiceProvider.php
use App\Validators\CustomValidator;
use App\Dependencies\Dependency;
use Illuminate\Support\ServiceProvider;
class AppServiceProvider extends ServiceProvider
{
    public function boot()
    {
        $this->app->bind('customValidator', function ($app) {
            return new CustomValidator(new Dependency());
        });
    }
}

php
// CustomValidator.php
namespace App\Validators;
use App\Dependencies\Dependency;
class CustomValidator
{
    protected $dependency;
    public function __construct(Dependency $dependency)
    {
        $this->dependency = $dependency;
    }
    public function validate($value)
    {
        // 自定义验证逻辑
    }
}

php
// 验证规则
Validator::extend('custom_rule', function ($attribute, $value, $parameters, $validator) {
    $customValidator = app('customValidator');
    return $customValidator->validate($value);
});