这个扩展在PHP 7.4.0中是不支持的，并且是不绑定的。PHP 7.4.0以前默认绑定开启 * [wddx\_add\_vars](https://www.php.net/manual/en/function.wddx-add-vars.php)—将变量添加到具有指定ID的WDDX数据包 * [wddx\_deserialize](https://www.php.net/manual/en/function.wddx-deserialize.php)—反序列化​​WDDX数据包 * [wddx\_packet\_end](https://www.php.net/manual/en/function.wddx-packet-end.php)—结束具有指定ID的WDDX数据包 * [wddx\_packet\_start](https://www.php.net/manual/en/function.wddx-packet-start.php)—启动一个内部结构新的WDDX数据包 * [wddx\_serialize\_value](https://www.php.net/manual/en/function.wddx-serialize-value.php)—将单个值序列化为WDDX数据包 * [wddx\_serialize\_vars](https://www.php.net/manual/en/function.wddx-serialize-vars.php)—将变量序列化为WDDX数据包 ``` header("Content-Type: text/xml;encoding=utf-8"); echo utf8_decode(wddx_serialize_value("안녕 하세요")); ```