在MSDN构造一个FileStream说，它可能会抛出要么是UnauthorizedAccessException或一个SecurityException。下面是MSDN说，有关这些异常。

The MSDN constructor for a FileStream says that it may throw either an UnauthorizedAccessException or a SecurityException. Here's what MSDN says about these exceptions.

UnauthorizedAccessException: 时引发的异常时，操作系统拒绝，因为一个I / O错误或安全错误的特定类型的访问。

UnauthorizedAccessException: The exception that is thrown when the operating system denies access because of an I/O error or a specific type of security error.

SecurityException: 所不同的是检测到安全错误时抛出。

SecurityException: The exception that is thrown when a security error is detected.

在这两个类似的异常有什么不同？什么情况下会触发他们要么？

How are these two similar exceptions different? What situations will trigger either of them?

推荐答案

A UnauthorizedAccessException 时出现权限错误访问磁盘上的文件抛出。这是操作系统级别的错误，如一个普通用户试图覆盖操作系统文件（比如kernel32.dll）。

A UnauthorizedAccessException is thrown when there is a permissions error accessing the file on disk. That is an error at the operating system level such as a normal user trying to overwrite an operating system file (like kernel32.dll).

A SecurityException异常被抛出。例如，如果你正在运行的低访问ClickOnce应用程序，并尝试读取/写入由CLR安全设置的过程中禁止的文件系统中的位置。

A SecurityException is thrown if there is a security violation at the CLR level. For example if you are running as a low access ClickOnce application and attempt to read / write to a place in the file system forbidden by the CLR security settings in the process.