---
title: OS_ACTIVITY_NONE
framework: os
role: symbol
role_heading: Macro
path: os/os_activity_none
---

# OS_ACTIVITY_NONE

A special value that indicates a nonexistent activity.

## Declaration

```occ
#define OS_ACTIVITY_NONE
```

## Discussion

Discussion When creating a new activity, pass this value as the activity’s parent to create the new activity as a top-level activity without a parent.

## See Also

### Choosing a Special Activity

- [OS_ACTIVITY_CURRENT](os/os_activity_current.md)