| 元素控件 | 尺寸（pts） | Window（含状态栏）320 x 480Status Bar的高度（横、竖屏）20Navigation Bar的高度（横屏）44Navigation Bar的高度（竖屏）32含Prompt的Navigation Bar的高度（横、竖屏）74Navigation Bar的图标20×20（透明的png）Tool Bar的高度（横屏）44Tool Bar的高度（竖屏）32Tool Bar的图标20×20（透明的png）Tab Bar的高度49Tab Bar的图标30×30（透明的png）竖屏时键盘的高度216、252（iOS 5+的中文键盘）横屏时键盘的高度162、198（iOS 5+的中文键盘）iPhone App Icon：
图标名称 | 尺寸 | 用途 | 是否必需 | Icon.png57×57App Store和iPhone、iPod touch桌面显示是Icon@2x.png114×114Icon.png的高清模式是Icon-Small.png29×29“设置”应用和Soptlight搜索否Icon-Small@2x.png58×58Icon-Small.png的高清模式否iPad App Icon：
图标名称 | 尺寸 | 用途 | 是否必需 | Icon-72.png72×72iPad桌面显示是Icon-50.png50×50Spotlight搜索否Icon-29.png29×29“设置”应用否iPhone、iPad通用App Icon：
图标名称 | 尺寸 | 用途 | 是否必需 | Icon.png57×57App Store和iPhone、iPod touch桌面显示是Icon-72.png72×72iPad桌面显示是Icon-50.png50×50iPad的Soptlight搜索否Icon-29.png29×29“设置”应用和iPhone、iPod touch的Soptlight搜索否
延伸阅读：Points VS. Pixels
The iPhone 4 introduced a high resolution display with twice the pixels of previous iPhones. However you don't have to modify your code to support high-res displays; the coordinate system goes by points rather than pixels, and the dimensions in points of the screen and all UI elements remain the same.
iOS 4 supports high resolution displays (like the iPhone 4 display) via the scale property on UIScreen, UIView, UIImage, and CALayer classes. If the object is displaying high-res content, its scale property is set to 2.0. Otherwise it defaults to 1.0.
All you need to do to support high-res displays is to provide @2x versions of the images in your project. See the checklist for updating to iOS4 or Apple documentation for Supporting High Resolution Screens for more info.
来自： http://dangpu.sinaapp.com/?p=59
