问题
I have iPhone app and I converted it in xcode4 to universal app, and it worked fine, but after that I deleted MainWindow-iPad and return to iPhone app only. Now I need to make my app universal again, I clicked in Xcode4 "Devices-Universal", but XCode don't create MainWindow-iPad and don't ask me "Transition to universal target" so when I'm building and running in iPad simulator app crashes. How can I fix this? Thank you.
回答1:
Create your own mainwindow-ipad nib file and set it as main nib file for the iPad platform in your info.plist
来源：https://stackoverflow.com/questions/5788286/how-to-convert-iphone-app-to-universal-in-xcode4-if-i-previously-converted-but