Reactjs 是否可以将MediaStream保存在react挂钩（useState）中？

我在WebRTC上工作。 我声明了一个变量localStream，如

var localStream;

组件外部。localStream最初包含MediaStream，但在调用信令服务器后调用我的回调函数时，变量localStream为空。我想将MediaStream存储在状态中，以便在调用信令服务器后它不会为空

在页面加载->本地流中包含流

从客户端我打电话，它呼叫信令服务器

它从信令服务器回调客户机，这里localStream为空

我尝试了useState（），useState（未定义）它不工作。它是空的

    import ....
const hubUrl = 'https://f1d3e599fe6c.ngrok.io/ConnectionHub';
const conn =
    new signalR.HubConnectionBuilder()
                    .withUrl(hubUrl, signalR.HttpTransportType.WebSockets)
        .configureLogging(signalR.LogLevel.Debug)
        .withAutomaticReconnect()
        .build();

var localStream;
var peerConnectionConfig = { iceServers: [{ url: 'stun:stun.l.google.com:19302' }] };

onst webrtcConstraints = { audio: true, video: true };
const Chat = (props) => {
    
    
    React.useEffect(() => {
...
}


      receivedSdpSignal = (connection, partnerClientId, sdp) => {
        console.log('WebRTC: processing sdp signal');
        console.log('sdp', sdp);
        connection.setRemoteDescription(new RTCSessionDescription(sdp)).then(() => {
            console.log('WebRTC: set Remote Description');
            if (connection.remoteDescription.type == "offer") {
                console.log('WebRTC: remote Description type offer');
                console.log('localStream', localStream);
                connection.addStream(localStream);
                console.log('WebRTC: added stream');
                connection.createAnswer().then((desc) => {
                    console.log('WebRTC: create Answer...');
                    console.log('WebRTC: Description...');
                    console.log(desc);
                    connection.setLocalDescription(desc).then(() => {
                        console.log('WebRTC: set Local Description...');
                        console.log(connection.localDescription);
                        this.sendHubSignal(JSON.stringify({ "sdp": connection.localDescription }), partnerClientId);
                    }).catch(err => console.log("WebRTC: Error while setting local description", err));
                }, err => console.log("WebRTC: Error while creating the answer", err));
            } else if (connection.remoteDescription.type == "answer") {
                console.log('WebRTC: remote Description type answer');
                }
            }).catch(err => console.log("WebRTC: Error while setting remote description", err));
        }

 const initializeUserMedia = () => {
        console.log('WebRTC: called initializeUserMedia: ');
        mediaDevices.getUserMedia(webrtcConstraints).then((stream) => {
          console.log("WebRTC: got media stream");
          localStream = stream;
          let audioTracks = localStream.getAudioTracks();
          if (audioTracks.length > 0) {
              console.log(`Using Audio device: ${audioTracks[0].label}`);
              
          }
        }).catch(err => console.log("Error getting user media stream.", err));
      }

---

此函数在useffect（）{}之外。本地流在此为空。

定义“不工作”，并显示您的代码。不工作-为空。很难从提供的代码中分辨问题，您必须添加整个文件，在localStream变量中设置媒体流的位置以及它变为空的位置。我希望您现在有一些想法。我添加了一些代码@阿卜海塞格尔