Question

我在我的React应用程序中使用Websockets，我必须连接到Web套接字，然后在连接后立即发送消息。但是我的代码不能同步工作

这是

ws = new WebSocket(uri);
ws.send('my msg');

有没有办法等待连接建立和就绪状态改变！谢谢！

Answer 1

来自the docs on MDN：

// Create WebSocket connection.
const socket = new WebSocket('ws://localhost:8080');

// Connection opened
socket.addEventListener('open', function (event) {
    socket.send('Hello Server!');
});

Answer 2

我正在做以下准备，以准备在许多其他地方使用WebSocket，不仅仅是在WebSocket readyState更改后立即：

// https://stackoverflow.com/questions/951021/what-is-the-javascript-version-of-sleep
const sleep = (ms) => {
  return new Promise(resolve => setTimeout(resolve, ms));
};

// (inside of async function)...

  const ws = new WebSocket(<webSocketServerUri>);

  let timeToConnect = 0;
  while (ws.readyState !== ws.OPEN) {
    await sleep(1);
    ++timeToConnect;
  };

  console.log('The WebSocket took ' + timeToConnect + ' milliseconds to connect.');

// (inside of async function)...
// ...
// (some other place in the code where 'ws' is accessible)...

  ws.send('my msg');

// (some other place in the code where 'ws' is accessible)...

HTML5 Websocket在发送消息之前等待连接和readystate更改

2 个答案: