It's more complicated code that requires extending a class to register an event listener.

它是更为复杂的代码，要求扩展类才能注册事件侦听程序。

youdao

It's more complicated code that requires extending a class to register an event listener.

它是更为复杂的代码，要求扩展类才能注册事件侦听程序。

youdao