public static function appShutdown()
{
if (!is_null($error = error_get_last()) && self::isFatal($error['type'])) {
// 将错误信息托管至think\ErrorException
$exception = new ErrorException($error['type'], $error['message'], $error['file'], $error['line']);
self::appException($exception);
}
// 写入日志
Log::save();
}