初识WebSocket：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>初识WebSocket</title>
</head>
<body>
<div style="margin-top: 30px;margin-left:30px">
<input type="text" id="info">
<button id="send">send</button>
<div id="notice"></div>
<div id="msg"></div>
</div>
</body>
<script>
var info = document.getElementById("info");
var send= document.getElementById("send");
var notice = document.getElementById("notice");
var msg = document.getElementById("msg");
var ws = new WebSocket("ws://echo.websocket.org/");
ws.onopen = function(){
notice.innerHTML = "connected";
}
ws.onclose = function(){
notice.innerHTML = "closed"
}
ws.onmessage = function(res){
console.log(res);
msg.innerHTML = res.data;
}
send.onclick = function(){
ws.send(info.value)
}
</script>
</html>
这个代码运行之后，在输入框中输入的数据都会原封不动的返回，因为使用的ws://echo.websocket.org/这个地址。