我刚刚开始学习websockets,我得到一个奇怪的错误：
<script type="text/javascript">
window.onload = function(){
var service = new WebSocket("ws://localhost:8080/websocket/test");
service.onmessage = function(event){
alert("message");
}
service.onopen = function(){
service.send("hello!");
}
service.onclose = function(){
alert("closed");
}
service.onerror = function(){
alert("error");
}
service.send("test");
service.close();
}
</script>
在线上：
service.send("test");
我明白了：
InvalidStateError: An attempt was made to use an object that is not,or is no longer,usable
我错过了重要的事吗？
解决方法
Once you’ve opened your connection,you can begin transmitting data to the server.
等待onopen事件！
window.onload = function() {
var service = new WebSocket("wss://echo.websocket.org");
service.onmessage = function(event) {
alert("onmessage event: "+event.data);
}
service.onopen = function() {
service.send("test"); //Will work here!
//^^^^^^^^^^^^^^^^^
service.send("hello!");
}
service.onclose = function() {
alert("closed");
}
service.onerror = function() {
alert("error");
}
//Can't close while a connection is still being established.
//service.close();
}
