> ## 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.

# XGameStreamingRegisterConnectionStateChanged

> XGameStreamingRegisterConnectionStateChanged

# XGameStreamingRegisterConnectionStateChanged

注册一个回调，当流式处理客户端设备的连接状态发生更改时调用该回调。注册后，将为所有已连接的流式处理客户端设备调用回调。

## 语法

```cpp theme={null}
HRESULT XGameStreamingRegisterConnectionStateChanged(  
         XTaskQueueHandle queue,  
         void* context,  
         XGameStreamingConnectionStateChangedCallback* callback,  
         XTaskQueueRegistrationToken* token  
)  
```

### 参数

*queue*   \_In\_opt\_\
类型：XTaskQueueHandle

用于放置更改回调的异步队列的句柄。

*context*   \_In\_opt\_\
类型：void\*

指向传递给回调函数的上下文的可选指针。

*callback*   \_In\_\
类型：XGameStreamingConnectionStateChangedCallback\*

当任何流式处理客户端设备的连接状态发生更改时将调用的回调函数。

*token*   \_Out\_\
类型：XTaskQueueRegistrationToken\*

指向可用于从事件中取消注册的注册令牌的指针。

### 返回值

类型：HRESULT

如果成功，则返回 **S\_OK**；否则返回错误代码。

#### 潜在错误

| 错误代码                               | 错误值        | 错误原因                                                                                                                                       |
| ---------------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| E\_GAMESTREAMING\_NOT\_INITIALIZED | 0x89245400 | XGameStreaming 运行时尚未初始化。在调用其他 API 之前，请先调用 [XGameStreamingInitialize](/reference/system/xgamestreaming/functions/xgamestreaminginitialize)。 |

有关错误代码列表，请参阅[错误代码](/reference/errorcodes)。

## 备注

<Note>在时间敏感线程上调用此函数并不安全。有关详细信息，请参阅[时间敏感线程](https://learn.microsoft.com/gaming/gdk/docs/gdk-dev/console-dev/overviews/threads/time-sensitive-threads)。</Note>

此 API 是建议的方式，可让游戏针对每个流式处理客户端设备进行自定义并维护状态，从而允许游戏根据是否有任何设备连接来优化体验。

<Note>注册后，将为所有当前已连接的流式处理客户端设备调用回调。</Note>

## 示例

```cpp theme={null}
    // Called during game startup to hook into any game streaming start/stop events
    void SetupStreamAware()
    {
        // Register a callback for client connections and disconnections. Note that the connection callback
        // will fire for any already connected clients, so do all of our per-client setup in that callback.      
        XGameStreamingConnectionStateChangedRegistrationToken stateChangeToken = {0};
        XGameStreamingRegisterConnectionStateChanged(
            m_taskQueue, this, ConnectionStateChangedCallback, &stateChangeToken);
    }

    static void ConnectionStateChangedCallback(void* context, XGameStreamingClientId client, XGameStreamingConnectionState state)
    {
        static_cast<Game*>(context)->OnConnectionStateChanged(client, state);
    }

    void OnConnectionStateChanged(XGameStreamingClientId client, XGameStreamingConnectionState state)
    {
        switch (state)
        {
        case XGameStreamingConnectionState::Connected: 
            OnClientConnected(client); 
            break;
        case XGameStreamingConnectionState::Disconnected: 
            OnClientDisconnected(client); 
            break;
        default: 
            break;
        }
    }


    void OnClientConnected(XGameStreamingClientId client)
    {
        // Update list of connected clients
        m_streamingClients.push_back(client);

        // Do per-client initialization
        // ...
    }

    void OnClientDisconnected(XGameStreamingClientId client)
    {
        // Release our reference on the client that is no longer streaming the game
        std::remove(m_streamingClients.begin(), m_streamingClients.end(), client);

        // Do per-client cleanup
        // ...
    }



```

## 要求

**标头：** xgamestreaming.h

**库：** xgameruntime.lib

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

## 概念性文档

* [云感知 API 调用](/build/core-features/common/game-streaming/game-streaming-am-i-streaming)
* [时间敏感线程](https://learn.microsoft.com/gaming/gdk/docs/gdk-dev/console-dev/overviews/threads/time-sensitive-threads)

## 另请参阅

[XGameStreamingConnectionState](/reference/system/xgamestreaming/enums/xgamestreamingconnectionstate)\
[XGameStreamingConnectionStateChangedCallback](/reference/system/xgamestreaming/functions/xgamestreamingconnectionstatechangedcallback)\
[XGameStreamingUnregisterConnectionStateChanged](/reference/system/xgamestreaming/functions/xgamestreamingunregisterconnectionstatechanged)\
[XGameStreaming](/reference/system/xgamestreaming/xgamestreaming_members)


## Related topics

- [XGameStreamingUnregisterConnectionStateChanged](/zh-CN/reference/system/xgamestreaming/functions/xgamestreamingunregisterconnectionstatechanged.md)
- [XGameStreamingConnectionStateChangedCallback](/zh-CN/reference/system/xgamestreaming/functions/xgamestreamingconnectionstatechangedcallback.md)
- [XGameStreamingConnectionState](/zh-CN/reference/system/xgamestreaming/enums/xgamestreamingconnectionstate.md)
- [XGameStreamingIsStreaming](/zh-CN/reference/system/xgamestreaming/functions/xgamestreamingisstreaming.md)
- [XGameStreamingGetConnectionState](/zh-CN/reference/system/xgamestreaming/functions/xgamestreaminggetconnectionstate.md)