Printing

Your app can take advantage of the system’s built-in AirPrint technology to enable wireless printing of images, PDFs, and other content to compatible printers. While viewing printable content in an AirPrint-enabled app, people typically tap an action button in a navigation bar or toolbar and then tap a Print action to display a printer view. This view provides a list of available printers and any customizable options, such as the number of copies and page range, and provides a button to initiate printing.

你的app可以利用系统内置的AirPrint技术来启用无线打印图片，PDF，和其他内容到兼容的打印机。当在一个支持AirPrint的app浏览可打印的内容时，用户一般敲击一个在导航或工具栏的操作按钮，然后敲击一个打印操作来显示打印视图。这个视图提供一系列可用的打印机和任何可定制的选项，例如复印的张数和页面范围，和提供一个按钮开始打印。

Make printing discoverable.Enable printing through the system-provided Action button if your app has a toolbar or navigation bar. Users are familiar with this button and use it to print in other apps. If your app doesn’t have a toolbar or navigation bar, design a custom print button instead.

使打印可发现。如果你的app有一个工具或导航栏通过系统提供的操作按钮激活打印。用户对这个按钮熟悉且在其他app也是用它来打印。如果你的app没有工具栏或导航栏，设计一个定制的按钮代替。

Enable printing only when it's possible to print.If there’s nothing onscreen to print or no printers are available, don’t show a Print action when someone taps the Action button. If your app implements a custom print button, disable or hide it when printing isn’t possible.

只有当它需要打印时才激活打印。如果屏幕上没有内容要打印或者没有打印机可用，不要显示一个打印操作当某人敲击操作按钮时。如果你的app实现一个定制的打印按钮，禁用或隐藏它当打印不可用时。

Provide printing options that add value.Think about the options people might want to specify when they print your content. Consider options for selecting a page range and requesting multiple copies. Enable additional options, such as front and back printing, if it makes sense and the printer supports them.

提供打印选项来增加值。考虑当用户打印你的内容可能需要定制。考虑选择一个页面范围和要求多份复制的选项。激活额外的选项，例如前后两面打印，如果这样有意义而且打印机支持。

For developer guidance, seeDrawing and Printing Guide for iOSandUIPrintInteractionController.