There\'a a similar question here but I couldn\'t make use of the answers in XCode 4. I googled it but I couldn\'t come up with anything useful either. What\'s your effective
I highly recommend you try appCode, by JetBrains. JetBrains have a lot of experience making IDEs (yes, even more than Apple ;) and have done an amazing job with even the EAP of appCode. Find usages, plus a lot more works very nicely.
You can simply open your existing xcode project file in appCode, then Search --> Find Usages.