webrtc 端到端文本聊天是在webRTC（十）：webrtc 實現web端對端視頻基礎上實現的，web端到端純文本聊天，後面有講到！
文本傳輸主要使用的是createDataChannel的api實現
- 創建 createDataChannel
socket.on('otherjoin',(roomid,id)=>{
...
var dataChannelOptions = {
ordered: true, //保證到達順序
};
//文本聊天
dc=pc.createDataChannel('dataChannel',dataChannelOptions);
dc.onmessage=reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
dc.onerror = dataChannelError;
...
});
在監聽對方進入房間後創建與對方連接的 DataChannel
//創建本地流媒體鏈接
function createPeerConnection(){
console.log('create RTCPeerConnection!');
if(!pc){
pc = new RTCPeerConnection(pcConfig);
...
//文本聊天
pc.ondatachannel = e =>{
// if(!dc){
dc= e.channel;
dc.onmessage =reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
dc.onerror = dataChannelError;
// }
}
...
}
}
創建本地流媒體鏈接時創建DataChannel
- 接收數據
//文本對方傳過來的數據
function reveivemsg(e){
var msg = e.data;
console.log('recreived msg is ：'+e.data);
if(msg){
chat.value += '->' + msg + '\r\n';
}else{
console.error('recreived msg is null');
}
}
- 監聽通道是否打通
function dataChannelStateChange(){
var readyState=dc.readyState;
if(readyState==='open'){
send_txt.disabled =false;
btnSend.disabled=false;
}else{
send_txt.disabled = true;
btnSend.disabled =true;
}
}
- 發送消息
//發送消息
function sendText(){
var data = send_txt.value;
if(data){
dc.send(data);
}
send_txt.value="";
chat.value += '<-' +data+'\r\n';
}
- 效果
源碼
- html
<html>
<head>
<title>WebRTC PeerConnection</title>
<style>
.preview{
display: flex;
}
.remote{
margin-left: 20px;
}
.text_chat{
display: flex;
}
.text_chat textarea{
width: 350px;
height: 350px;
}
.send{
margin-top: 20px;
}
</style>
</head>
<body>
<div>
<div>
<button id="connserver">Connect Sig Server</button>
<button id="leave" disabled>Leave</button>
</div>
<div class="preview">
<div>
<h2>Local:</h2>
<video id="localvideo" autoplay playsinline></video>
</div>
<div class="remote">
<h2>Remote:</h2>
<video id="remotevideo" autoplay playsinline></video>
</div>
</div>
<!--文本聊天-->
<h2>Chat:</h2>
<div class="text_chat">
<div>
<textarea id="chat" disabled></textarea>
</div>
<div class="remote">
<textarea id="sendtext" disabled></textarea>
</div>
</div>
<div class="send">
<button id="send" disabled>Send</button>
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.3/socket.io.js"></script>
<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script>
<script src="./js/client.js"></script>
</body>
</html>
- js
'use strict'
var localVideo = document.querySelector('video#localvideo');
var remoteVideo = document.querySelector('video#remotevideo');
var btnConn = document.querySelector('button#connserver');
var btnLeave = document.querySelector('button#leave');
// 文本聊天
var chat = document.querySelector('textarea#chat');
var send_txt = document.querySelector('textarea#sendtext');
var btnSend = document.querySelector('button#send');
var localStream = null;
var roomid = '555555';
var socket =null;
var state = 'init';
var pc = null;
var dc = null;
var pcConfig={
'iceServers':[{
'urls':'turn:121.41.76.43:3478',
'credential':'123456',
'username':'huang'
}]
}
function sendMessage(roomid,data){
if(socket){
socket.emit('message',roomid,data);
}
}
function getAnswer(desc){
pc.setLocalDescription(desc);
sendMessage(roomid,desc);
}
function handleAnswerError(err){
console.error('Failed to get Answer!',err);
}
function getOffer(desc){
pc.setLocalDescription(desc);
sendMessage(roomid,desc)
}
function handleOfferError(err){
console.error('Failed to get Offer!',err);
}
//接收遠端流通道
function call(){
if(state === 'joined_conn'){
if(pc){
var options = {
offerToReceiveAudio:1,
offerToReceiveVideo:1
}
pc.createOffer(options)
.then(getOffer)
.catch(handleOfferError);
}
}
}
// 第一步：開始服務
function connSignalServer(){
//開啓本地視頻
start();
return true;
}
//文本對方傳過來的數據
function reveivemsg(e){
var msg = e.data;
console.log('recreived msg is ：'+e.data);
if(msg){
chat.value += '->' + msg + '\r\n';
}else{
console.error('recreived msg is null');
}
}
function dataChannelStateChange(){
var readyState=dc.readyState;
if(readyState==='open'){
send_txt.disabled =false;
btnSend.disabled=false;
}else{
send_txt.disabled = true;
btnSend.disabled =true;
}
}
function dataChannelError(error){
console.log("Data Channel Error:", error);
}
function conn(){
//1 觸發socke連接
socket = io.connect();
//2 加入房間後的回調
socket.on('joined',(roomid,id)=>{
state = 'joined';
createPeerConnection();
btnConn.disabled = true;
btnLeave.disabled =false;
console.log("reveive joined message:state=",state);
});
socket.on('otherjoin',(roomid,id)=>{
if (state === 'joined_unbind') {
createPeerConnection();
}
var dataChannelOptions = {
ordered: true, //保證到達順序
};
//文本聊天
dc=pc.createDataChannel('dataChannel',dataChannelOptions);
dc.onmessage=reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
dc.onerror = dataChannelError;
state = 'joined_conn';
//媒體協商
call();
console.log("reveive otherjoin message:state=",state);
});
socket.on('full',(roomid,id)=>{
console.log('receive full message ', roomid, id);
closePeerConnection();
closeLocalMedia();
state = 'leaved';
btnConn.disabled = false;
btnLeave.disabled = true;
console.log("reveive full message:state=",state);
alert("the room is full!");
});
socket.on('leaved',(roomid,id)=>{
state = 'leaved';
socket.disconnect();
btnConn.disabled = false;
btnLeave.disabled = true;
console.log("reveive leaved message:state=",state);
});
socket.on('bye',(roomid,id)=>{
state = 'joined_unbind';
closePeerConnection();
console.log("reveive bye message:state=",state);
});
socket.on('disconnect', (socket) => {
console.log('receive disconnect message!', roomid);
if(!(state === 'leaved')){
closePeerConnection();
closeLocalMedia();
}
state = 'leaved';
});
socket.on('message',(roomid,id,data)=>{
console.log(" message=====>",data);
//媒體協商
if(data){
if(data.type === 'offer'){
pc.setRemoteDescription(new RTCSessionDescription(data));
pc.createAnswer()
.then(getAnswer)
.catch(handleAnswerError);
}else if(data.type === 'answer'){
console.log("reveive client message=====>",data);
pc.setRemoteDescription(new RTCSessionDescription(data));
}else if(data.type === 'candidate'){
var candidate = new RTCIceCandidate({
sdpMLineIndex:data.label,
candidate:data.candidate
});
pc.addIceCandidate(candidate);
}else{
console.error('the message is invalid!',data)
}
}
console.log("reveive client message",roomid,id,data);
});
socket.emit('join',roomid);
return;
}
// 撲捉本地視頻
function getMediaStream(stream){
localStream =stream;
//2 ===============顯示本地視頻===============
localVideo.srcObject = localStream;
//這個函數的調用時機特別重要 一定要在getMediaStream之後再調用，否則會出現綁定失敗的情況
conn();
}
function handleError(err){
if(err){
console.error("getUserMedia error:",err);
}
}
// 第二步：採集本地視頻
function start(){
if (!navigator.mediaDevices||
!navigator.mediaDevices.getUserMedia) {
console.log("getUserMedia is not supported!")
return;
} else {
//1 ===============配置音視頻參數===============
var constraints={
video:true,
audio: false
}
navigator.mediaDevices.getUserMedia(constraints)
.then(getMediaStream)
.catch(handleError)
}
}
//關閉流通道
function closeLocalMedia(){
if (localStream&&localStream.getTracks()) {
localStream.getTracks().forEach((track)=>{
track.stop();
});
}
localStream = null;
}
function leave(){
if(socket){
socket.emit('leave',roomid);
}
//釋放資源
closePeerConnection();
closeLocalMedia();
btnConn.disabled = false;
btnLeave.disabled = true;
}
//創建本地流媒體鏈接
function createPeerConnection(){
console.log('create RTCPeerConnection!');
if(!pc){
pc = new RTCPeerConnection(pcConfig);
pc.onicecandidate = (e) =>{
if(e.candidate){
sendMessage(roomid,{
type:'candidate',
label:e.candidate.sdpMLineIndex,
id:e.candidate.sdpMid,
candidate:e.candidate.candidate
});
}
}
//文本聊天
pc.ondatachannel = e =>{
// if(!dc){
dc= e.channel;
dc.onmessage =reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
dc.onerror = dataChannelError;
// }
}
pc.ontrack = (e)=>{
remoteVideo.srcObject = e.streams[0];
}
}
if(pc === null || pc === undefined){
console.error('pc is null or undefined!');
return;
}
if(localStream === null || localStream === undefined){
console.error('localStream is null or undefined!');
return;
}
if(localStream){
localStream.getTracks().forEach((track)=>{
pc.addTrack(track,localStream);
})
}
}
//關閉本地媒體流鏈接
function closePeerConnection(){
console.log('close RTCPeerConnection!');
if(pc){
pc.close();
pc = null;
}
}
//發送文本
function sendText(){
var data = send_txt.value;
if(data){
dc.send(data);
}
send_txt.value="";
chat.value += '<-' +data+'\r\n';
}
btnConn.onclick = connSignalServer;
btnLeave.onclick = leave;
btnSend.onclick=sendText;