嗨 当您使用SystemEvents访问系统操作时，而OS并未访问您的应用程序.因此，每次您需要通过拨打电话手动获取更改信息时.
因此，您可以使用计时器定期访问它.

Hi as you are accessing the system operations using SystemEvents but OS is not accessing your application. so each time you need to manually get the changes information by making a call.
so, you may use timer to access it periodically.