CFUUIDRef theUUID = CFUUIDCreate(NULL); CFStringRef guid = CFUUIDCreateString(NULL, theUUID);

CFUUIDRef theUUID = CFUUIDCreate(NULL);

CFStringRef guid = CFUUIDCreateString(NULL, theUUID);

CFRelease(theUUID);

NSString uuidString = [((NSString )guid) stringByReplacingOccurrencesOfString:@”-” withString:@”“];

CFRelease(guid);

爲了能標識該字符串，所以一般使用一個固定的字符串來標誌

• (NSString )pathForTemporaryFileWithPrefix:(NSString )prefix
  {
  NSString * result;
  CFUUIDRef uuid;
  CFStringRef uuidStr;
  uuid = CFUUIDCreate(NULL);
  assert(uuid != NULL);
  uuidStr = CFUUIDCreateString(NULL, uuid);
  assert(uuidStr != NULL);
  result = [NSTemporaryDirectory()stringByAppendingPathComponent:[NSStringstringWithFormat:@”%@-%@”, prefix, uuidStr]];
  assert(result != nil);
  CFRelease(uuidStr);
  CFRelease(uuid);
  return result;
  }