这两天开发iOS app用到了Tab bar，然后随便切了点图标放上去发现效果极差。于是乎，开始查找苹果官方给的标准。搜索一番后，看到了一篇博文，但其内容与iOS人机交互指南最新版内容不符。
故此，在下面列出iOS Human Interface Guidelines最新版中的尺寸标准，具体索引为Icon and Image Design-> Icon and Image Size
“Every app needs an app icon and a launch file or image. In addition, some apps need custom icons to represent app-specific content, functions, or modes in navigation bars, toolbars, and tab bars.
每个应用都需要一个应用图标和一个启动文件或启动图片。此外，一些应用需要使用自定义图标在导航栏、工具栏和tab bar中展示特别的内容，功能或者风格。
Unlike other custom artwork in your app, the icons and images listed in Table 41-1 must meet specific criteria so that iOS can display them properly. In addition, some icon and image files have naming requirements (to learn about naming these files, see App Icons in App Programming Guide for iOS and App Launch (Default) Images in App Programming Guide for iOS).”
和其他你在应用中自定义的artwork不同，为了iOS能够正确的显示，下面表中列出的图标和图片需要符合特殊的标准。另外，一些图标和图片文件必须满足命名要求。（为了了解更多，请看App Icons in App Programming Guide for iOS and App Launch(Default) Images in App Programming Guide for iOS）
摘录来自: Apple Inc. “iOS Human Interface Guidelines”。 iBooks. https://itun.es/cn/pyfv0.l
