iOS很聰明 ipad跟iphone的影像檔 只要按照官方的naming rule 他就會幫你自動挑選合適的影像 Example: For devices without retina: ImageName.png - For iPhone/iPod ImageName~ipad.png -- For iPad For devices with retina display: ImageName@2x.png - For iPhone/iPod ImageName@2x~ipad.png -- For iPad 程式只需要寫 [UIImage imageNamed:@"ImageName.png"]; icon Size的部份 57 px, iPhone – Good ol』 classic. 114 px, Retina iPhone 72 px, iPad 144 px, Retina iPad 29 px, iPhone Settings/Spotlight, iPad Settings – Used in these table views. Minor, but still important! 58 px, iPhone 4 Settings/Spotlight/Notifications – That's right, you have to make both 57 and 58 px versions of your icon – d』oh! Good luck aligning this if there's a line running down the middle of the icon. 48 px, iPad Spotlight – Yup, the iPad uses a different size for Spotlight and Settings. Apple's docs actually say the icon is 50 px, but then there's this not...