请问怎么获取一个分组里的全部信息？

CFErrorRef error = NULL;
ABAddressBookRef addrBook = ABAddressBookCreate();
CFArrayRef groups = ABAddressBookCopyArrayOfAllGroups(addrBook);
CFIndex numGroups = CFArrayGetCount(groups);
for(CFIndex idx=0; idx<numGroups; ++idx) {
ABRecordRef groupItem = CFArrayGetValueAtIndex(groups, idx);

CFArrayRef members = ABGroupCopyArrayOfAllMembers(groupRef);
if(members) {
    NSUInteger count = CFArrayGetCount(members);
    for(NSUInteger idx=0; idx<count; ++idx) {
        ABRecordRef person = CFArrayGetValueAtIndex(members, idx);

        // your code
    }
    CFRelease(members);
  }
}

CFRelease(groups);
CFRelease(addrBook);