出自UXGuide.net

灵活

Adaptability

An adaptable program is one that adjusts appropriately to its surroundings; that is, it does not stop working when the current conditions change. If a network connection goes down, an adaptable program lets the user continue to work offline. Similarly, if certain resources are locked or become unavailable, an adaptable program finds other ways to meet the user’s request.

一个灵活的程序就是能够适应它的环境的程序，也就是说，即使目前的情况改变了，它仍然能够工作。如果网络连接断开了，一个具有良好的适应性的程序可以让用户继续在脱机模式下工作。类似的，如果某个资源被锁定或者不可用，具有良好适应性的程序会寻找其他途径来满足用户的要求。

One of the strengths of Mac OS X is its ability to adapt to configuration changes quickly and easily. For example, if the user changes a computer’s network configuration from System Preferences, the changes are automatically picked up by applications such as Safari and Mail, which use CFNetwork to handle network configuration changes automatically.

Mac OS X一个强大的地方就是能够快速方便的适应配置环境的变化。例如，如果用户在系统偏好设置中改变了网络的配置，使用CFNetwork框架的应用程序如Safari，Mail都能自动的应用新的网络配置。

Here are some guidelines to keep in mind as you design your software to be adaptable:

下面是设计具有良好适应性程序的一些准则：

• Build forgiveness and intelligence into your interface. Make sure your software can handle cases in which a file-system volume or the network disappears. Offer the user an option for saving files to a different volume or reconnecting to the network later.

在您的接口设计中提供容错性和灵活性考虑。确保在文件系统中的卷宗或者网络断开时您的软件能够提供将文件保存到其他卷宗或者稍后重新连接的选项。

• Avoid making assumptions about available hardware and access to that hardware. Hardware configurations can vary greatly based on the computer, country, and user. For example, not every Macintosh is equipped with Velocity Engine on the processor. Similarly, not all keyboards have the same set of keys. Hardware can also be added or removed at runtime. Use the I/O Kit interfaces to detect available device configurations. See Accessing Hardware From Applications for more information.

避免假设硬件的存在并直接访问该硬件。硬件配置很大程度上随计算机、国家、用户的不同而不同。例如，不是每个 Macintosh 计算机都在处理器上装备了加速引擎（速度计）。类似的，不是所有的键盘都是同样的键盘配置。用户可能在运行时增加和删减硬件。使用 I/O Kit 接口来检测可用的设备配置。更多信息请参考在程序中访问硬件。

• Avoid making assumptions based on the current user’s locale. Be prepared to handle different date, time, and number formats. Also, don’t assume that the address format of the current user is the only address format in use. For example, the user may store contacts with foreign addresses in Address Book.

不要只考虑当前用户的语言环境。处理不同格式的日期、时间和数字。同样，不要假设当前用户的地址格式就是唯一使用的地址格式。例如，用户在地址簿中保存的联系人中可能具有国外地址。

• Avoid making assumptions about your execution environment. If your program is running in a NetBoot environment, your access to the system resources may be limited or read-only. For example, in a typical NetBoot environment, only the user’s home directory is writable.

不要对您的运行环境做出假设。如果您的程序运行在网络启动的环境中，系统资源可能只能只读地访问，甚至不能访问。例如，在典型的网络启动环境中，只有用户的主目录是可写的。

• Use Bonjour to automatically discover devices and network services on IP networks. Don’t make the user type in an IP address or configure a DNS server.
• Be sensitive to changes in screen availability and resolution. Mac OS X supports hot-plugging of monitors and notifies applications of the changes through Quartz Services. Your software should respond appropriately by adjusting window locations and dimensions as described in “Window Behavior.”

随时检测屏幕的可用性及其分辨率。Mac OS X 支持热插拔显示器，并且通过 Quartz 服务来通知应用程序这一变化。您的程序需要正确的调整窗口的位置和坐标，具体信息请参考“[[macos:window-behavior|窗口的行为”。

• Use modern system APIs. Apple works to ensure that its modern system APIs properly handle configuration changes. Although some legacy APIs may also support configuration changes, that support may change in future releases.

使用新的系统 API。Apple 只保证新的系统 API 能够正确的处理配置的改变。尽管有些早期的 API 也能支持这一点，然而在将来的版本中他们可能不再支持。

• Avoid writing custom device drivers. The I/O Kit contains working drivers to support many standard protocols and device types. Relying on these drivers means your hardware should automatically work with each new version of Mac OS X.

避免编写定制的设备驱动。I/O Kit 已经包含了很多标准的协议和设备的驱动。如果使用这些标准驱动意味着您的硬件可以工作在每个新版本的 Mac OS X 中。