Shared (file may be opened by other applications), Lock Read (file is protected against reading), Lock Write (file is protected against writing), Lock Read Write (denies file access).
Protected：指定文件打开后的安全状态的关键字。有效值：Shared（文件可以被其他应用程序打开）、Lock Read（文件受读取保护）、Lock Write（文件受写入保护）、Lock Read Write（拒绝对文件进行访问）。