Xcode4.2產生app支援舊版iOS裝置

先說一下armv6 與 armv7的區別:

What is ARMv7?
It's a new CPU architecture of iPhone. Make some apps run faster.

What does ARMv7 to do with me?
Here is a post by most_Unique found on iPhoneCake.

Most apps today use FAT binary which cracked on ARMv7 device will not work on ARMv6 device.

• Armv7的機器有：iPhone4, iPhone4s, iPad, iPad2, iPhone 3GS, iPod 3G
• Armv6的機器有：iPhone 2G, iPhone3G, iPod 1G, iPod2G

那麼要在老機器上跑, 比如iphone3G, 就必須支援armv6

Xcode 4.2的Architectures設定預設只有armv7

解決方案：將Architectures設定為armv6 armv7，

修改前：

修改後：

這樣設定後產生的ipa安裝包就可以支援舊版iOS裝置了。