Retrieves the value of an environment variable 检索环境变量的值。
2.
Retrieves the value of an environment variable from the current process 从当前进程检索环境变量的值。
3.
Retrieves the value of an environment variable from the current process or from the windows operating system registry key for the current user or local machine 从当前进程或者从当前用户或本地计算机的windows操作系统注册表项检索环境变量的值。
4.
Object is used to set or retrieve the ambient transaction and the application must manually set it to ensure that resource managers can participate in the transaction 属性用于设置或检索环境事务，并且应用程序必须手动设置它，以确保资源管理器可以参与该事务。
