用ios sdk 4制作的应用程序是否安装在带有操作系统4.2的设备上？

Question

Does an app that made with ios sdk 4 install on device with os 4.2 ?

I made an app with ios sdk 4.0.1 but now i want to install it from xcode on ipod touch with os 4.2 but says No provisioned iPhone OS device is connected.

Answer 1

Yes. You can run Applications for previous versions of iOS on a device with iOS 4.2.

The other way around might not be true: you may not be able to run applications compiled specifically for iOS 4.2 on devices with previous versions of iOS.

Keep in mind that with iOS 4.2 SDK you CAN create applications for devices running lower version of iOS also. It depends on how you configure your project on info.plist and the APIs you use in your application.

Answer 2

Yes. There might be few cases of incompatibility, but they are very rare.

Edit: And in most cases, apps build against 4.2 will run on 4.0 just fine, if they use the new stuff wisely.

Answer 3

In almost all circumstances your app should run. Its very unlikely for it to produce any errors.