This is diving me crazy - I've copied a target for my iOS project in Xcode4 - however, the Target Identifier field under "iOS Application Target" on the Summary page for my target is uneditable.
How do I change the target's identifier?
It gets the identifier from the product name. Go into build settings, then scroll down to the Packaging section. Change the product name and the identifier will change accordingly.
来源：https://stackoverflow.com/questions/5725075/xcode4-ios-copied-a-target-why-cant-i-change-the-identifier