UUID

获取UUID的方法
方法1，UIDevice.uuid
[UIDevice currentDevice].identifierForVendor.UUIDString

方法2，C语言

• (NSString *)getUUIDString
  {
  CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
  CFStringRef strRef = CFUUIDCreateString(kCFAllocatorDefault , uuidRef);
  NSString uuidString = [(__bridge NSString)strRef stringByReplacingOccurrencesOfString:@"-" withString:@""];
  CFRelease(strRef);
  CFRelease(uuidRef);
  return uuidString;
  }

C语言UUID=DCA3DBA5729B480BA4F018E228A7DD1C -- UIDevice.uuid=E0634708-077D-4D44-B5FA-268D56B434CE

C语言UUID=C6BB03935D774C3FBEDE3F8DC5C9CA66 -- UIDevice.uuid=E0634708-077D-4D44-B5FA-268D56B434CE

手机系统升级后方法2的UUID会变，方法1的UUID不会变。