> ## 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

应用程序为用户更改事件定义的回调。

## 语法

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

### 参数

*context*   \_In\_opt\_\
类型：void\*

应用程序定义并发送给 [XUserRegisterForChangeEvent](/reference/system/xuser/functions/xuserregisterforchangeevent) 的上下文。

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

在游戏会话期间存在的用户的唯一标识符。

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

指定用户更改事件类型的枚举。

## 注解

若要获取注销延迟，请调用 [XUserChangeEventCallback](/reference/system/xuser/functions/xuserchangeeventcallback)。请确保将 [*XUserChangeEvent*](/reference/system/xuser/enums/xuserchangeevent) 设置为 [XUserChangeEvent::SigningOut](/reference/system/xuser/enums/xuserchangeevent)。

只有对于通过调用 [XUserAddAsync](/reference/system/xuser/functions/xuseraddasync) 添加到标题中的用户，才会调用此回调。

以下示例演示了如何处理用户更改事件。

```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);
    }
}
```

类型：void

## 要求

**头文件：** XUser.h

**库：** xgameruntime.lib

**支持的平台：** Windows、Steam Deck、XBOX One 系列主机和 XBOX Series 主机

## 另请参阅

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


## Related topics

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