> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# XUserChangeEventCallback

> XUserChangeEventCallback

# XUserChangeEventCallback

A callback that an application defines for a user change event.

## Syntax

```cpp theme={null}
void XUserChangeEventCallback(  
         void* context,  
         XUserLocalId userLocalId,  
         XUserChangeEvent event  
)  
```

### Parameters

*context*   \_In\_opt\_\
Type: void\*

A context that the application defines and sends to [XUserRegisterForChangeEvent](/reference/system/xuser/functions/xuserregisterforchangeevent).

*userLocalId*   \_In\_\
Type: [XUserLocalId](/reference/system/xuser/structs/xuserlocalid)

A unique identifier for a user that exists for the game session.

*event*   \_In\_\
Type: [XUserChangeEvent](/reference/system/xuser/enums/xuserchangeevent)

An enumeration specifying the type of user change event.

## Remarks

To obtain a sign out deferral, call [XUserChangeEventCallback](/reference/system/xuser/functions/xuserchangeeventcallback). Make sure to set [*XUserChangeEvent*](/reference/system/xuser/enums/xuserchangeevent) to [XUserChangeEvent::SigningOut](/reference/system/xuser/enums/xuserchangeevent).

This callback will only be called for users that were added to the title with a call to [XUserAddAsync](/reference/system/xuser/functions/xuseraddasync).

The following example demonstrates how to handle user change events.

```cpp theme={null}
HRESULT RegisterForChanges()
{
    RETURN_HR_IF(E_UNEXPECTED, _token.token != 0);
    RETURN_IF_FAILED(XUserRegisterForChangeEvent(
        _queue,
        this,
        UserChangeEventHandler,
        &_token));
    return S_OK;
}

void UnregisterForChanges()
{
    XUserUnregisterForChangeEvent(_token, false);
    _token.token = 0;
}

void UserChangeEventHandler(
    XUserLocalId userLocalId,
    XUserChangeEvent event)
{
    auto iter = std::find_if(
        _users.begin(),
        _users.end(),
        [&userLocalId](const User& candidate)
    {
        XUserLocalId candidateUserLocalId;
        XUserGetLocalId(candidate.Handle(), &candidateUserLocalId);
        return candidateUserLocalId == userLocalId;
    });

    // User not known
    if (iter == _users.end())
    {
        return;
    }

    auto handle = iter->Handle();

    // If a guest gets signed out, immediately close the handle
    bool isGuest;
    if (SUCCEEDED_LOG(XUserGetIsGuest(handle, &isGuest)) &&
        isGuest &&
        event == XUserChangeEvent::SignedOut)
    {
        _users.erase(iter);
    }

    if (event == XUserChangeEvent::SigningOut)
    {
        // Delay the user signing out just for fun
        XUserSignOutDeferralHandle deferral;
        if (SUCCEEDED_LOG(XUserGetSignOutDeferral(&deferral)))
        {
            // Hold the deferral for 5 seconds then close it
            std::thread completeDeferralThread(
                [deferral]()
            {
                std::this_thread::sleep_for(std::chrono::milliseconds(5000));
                XUserCloseSignOutDeferralHandle(deferral);
            });

            completeDeferralThread.detach();
        }
    }

    if (event == XUserChangeEvent::GamerPicture)
    {
        iter->LoadGamerPicAsync(_queue);
    }
}
```

Type: void

## Requirements

**Header:** XUser.h

**Library:** xgameruntime.lib

**Supported platforms:** Windows, Steam Deck, XBOX One family consoles and XBOX Series consoles

## See also

[XUser](/reference/system/xuser/xuser_members)


## Related topics

- [XUserChangeEvent](/reference/system/xuser/enums/xuserchangeevent.md)
- [XUserRegisterForChangeEvent](/reference/system/xuser/functions/xuserregisterforchangeevent.md)
- [XUserUnregisterForChangeEvent](/reference/system/xuser/functions/xuserunregisterforchangeevent.md)
- [XUserGetSignOutDeferral](/reference/system/xuser/functions/xusergetsignoutdeferral.md)
- [XUserLocalId](/reference/system/xuser/structs/xuserlocalid.md)