如果我的代码包含在try catch块中，则`set_exception_handler`仍然有用吗？

Question

我的应用程序入口点中包含以下代码：

try {
    /**
     * Throws an exception depending on the triggered E_* error type.
     */
    $errorHandler = function($errno, $errstr, $errfile, $errline, $errcontext) {
        $errorReporting = error_reporting();
        if (
            // The error was suppressed with the `@` operator
            (0 === $errorReporting)
            ||
            // The error code is not included in error_reporting
            (!($errorReporting & $errno))
        ) {
            return false;
        }

        // TODO: Differentiate between the case when this code is executed as the result of an error
        //             which is handled through the `register_shutdown_function` callback.
        throw new \Exception($errstr);
    };
    set_error_handler($errorHandler);

    /**
    * Checks for an error which cannot be handled by the handler set through `set_error_handler`.
    */
    $shutdownHandler = function() use (&$errorHandler) {
        $error = error_get_last();
        if (
            $error["type"] == E_ERROR
            ||
            $error["type"] == E_PARSE
            ||
            $error["type"] == E_CORE_ERROR
            ||
            $error["type"] == E_CORE_WARNING
            ||
            $error["type"] == E_COMPILE_ERROR
            ||
            $error["type"] == E_COMPILE_WARNING
            ||
            $error["type"] == E_STRICT
        ) {
            $errorHandler($error["type"], $error["message"], $error["file"], $error["line"], []);
        }
    };
    register_shutdown_function($shutdownHandler);

    ...
}
catch (\Throwable $ex) {
    echo '<pre>' . $ex . '</pre>';
}

我的目标是捕获所有PHP错误，异常以及所有内容（甚至包括Fatal error: Allowed memory size of xxx bytes exhausted之类的错误，我可以通过register_shutdown_function捕获这些错误），以便使我能够处理所有应用程序的错误/异常（我想显示一个自定义的500页）。

到目前为止，我还没有使用set_exception_handler。考虑到我已经将整个应用程序的代码包装在try-catch块中，我想知道是否应该使用它。有必要吗？

感谢您的关注。