Silex:调用$app->；中间件中的abort(）返回500 - Silex: Calling $app->abort() in a middleware returns 500

Silex: Calling $app->abort() in a middleware returns 500

我不想使用条令等。所以，我只是使用PDO。问题是我不知道如何处理异常：调用$app->abort以表明它在路由之外不工作。

<?php
require_once __DIR__.'/../vendor/autoload.php'; 
use Symfony'Component'HttpFoundation'Response;
use Symfony'Component'HttpFoundation'Request;
$app = new Silex'Application();
//PDO
try {
    $DBH = new PDO($PartCCTV_ini['db']['dsn'], $PartCCTV_ini['db']['user'], $PartCCTV_ini['db']['password']);
}
catch(PDOException $e) {
    $app->abort(500, 'PDO Error : '.$e->getMessage());            
} 
...
$app->run()
?>

//PDO
try {
    $DBH = new PDO($PartCCTV_ini['db']['dsn'], $PartCCTV_ini['db']['user'], $PartCCTV_ini['db']['password']);
}
catch(PDOException $e) {
    $Exception = $e->getMessage();    
    $app->before(function () use($Exception) {
        throw new PDOException($Exception);
    });
}

"科尔霍兹风格"（俄语），但它有效！