laravel 用中间件解决能够处理正常跨域问题，但当出现异常的时候大家是怎么处理的呢？

[wangwenfan]

处理跨域用的官方的barryvdh/laravel-cors包，但试了下 HttpException 的 header 属性上写死加上Access-Control-Allow-Origin'=>'*'还是不行。

namespace Symfony\Component\HttpKernel\Exception;

/**
 * HttpException.
 *
 * @author Kris Wallsmith <[e-mail]>
 */
class HttpException extends \RuntimeException implements HttpExceptionInterface
{
    private $statusCode;
    private $headers;

    public function __construct($statusCode, $message = null, \Exception $previous = null, array $headers = [], $code = 0)
    {
        $this->statusCode = $statusCode;
        $this->headers = ['Access-Control-Allow-Origin'=>'*'];

        parent::__construct($message, $code, $previous);
    }

[jswh]

找到 ExceptionHandler，去哪里改 render 函数，加上 header