如何启动基本的WebRTC数据通道？

Question

如何启动基本的WebRTC数据通道？

这是我到目前为止所做的,但它似乎甚至没有试图连接.我确定我只是遗漏了一些基本的东西.

var RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection || window.msRTCPeerConnection;

var peerConnection = new RTCPeerConnection({
    iceServers: [
        {url: 'stun:stun1.l.google.com:19302'},
        {url: 'stun:stun2.l.google.com:19302'},
        {url: 'stun:stun3.l.google.com:19302'},
        {url: 'stun:stun4.l.google.com:19302'},
    ]
});
peerConnection.ondatachannel  = function () {
    console.log('peerConnection.ondatachannel');
};
peerConnection.onicecandidate = function () {
    console.log('peerConnection.onicecandidate');
};

var dataChannel = peerConnection.createDataChannel('myLabel', {
});

dataChannel.onerror = function (error) {
    console.log('dataChannel.onerror');
};

dataChannel.onmessage = function (event) {
    console.log('dataChannel.onmessage');
};

dataChannel.onopen = function () {
    console.log('dataChannel.onopen');
    dataChannel.send('Hello World!');
};

dataChannel.onclose = function () {
    console.log('dataChannel.onclose');
};
console.log(peerConnection, dataChannel);

Answer 1

WebRTC假设您有办法向您想要联系的任何人发送信号(向其发送要约字符串,并从中接收答案字符串).没有一些服务器,你会怎么做？

为了说明,这里有一些代码可以执行除此之外的所有操作(适用于Firefox和Chrome 45):

var config = { iceServers: [{ urls: "stun:stun.l.google.com:19302" }]};
var dc, pc = new RTCPeerConnection(config);
pc.ondatachannel = e => {
  dc = e.channel;
  dc.onopen = e => (log("Chat!"), chat.select());
  dc.onmessage = e => log(e.data);
}

function createOffer() {
  button.disabled = true;
  pc.ondatachannel({ channel: pc.createDataChannel("chat") });
  pc.createOffer().then(d => pc.setLocalDescription(d)).catch(failed);
  pc.onicecandidate = e => {
    if (e.candidate) return;
    offer.value = pc.localDescription.sdp;
    offer.select();
    answer.placeholder = "Paste answer here";
  };
};

offer.onkeypress = e => {
  if (e.keyCode != 13 || pc.signalingState != "stable") return;
  button.disabled = offer.disabled = true;
  var obj = { type:"offer", sdp:offer.value };
  pc.setRemoteDescription(new RTCSessionDescription(obj))
  .then(() => pc.createAnswer()).then(d => pc.setLocalDescription(d))
  .catch(failed);
  pc.onicecandidate = e => {
    if (e.candidate) return;
    answer.focus();
    answer.value = pc.localDescription.sdp;
    answer.select();
  };
};

answer.onkeypress = e => {
  if (e.keyCode != 13 || pc.signalingState != "have-local-offer") return;
  answer.disabled = true;
  var obj = { type:"answer", sdp:answer.value };
  pc.setRemoteDescription(new RTCSessionDescription(obj)).catch(failed);
};

chat.onkeypress = e => {
  if (e.keyCode != 13) return;
  dc.send(chat.value);
  log(chat.value);
  chat.value = "";
};

var log = msg => div.innerHTML += "<p>" + msg + "</p>";
var failed = e => log(e + ", line " + e.lineNumber);

<script src="https://rawgit.com/webrtc/adapter/master/adapter.js"></script>
<button id="button" onclick="createOffer()">Offer:</button>
<textarea id="offer" placeholder="Paste offer here"></textarea><br>
Answer: <textarea id="answer"></textarea><br><div id="div"></div>
Chat: <input id="chat"></input><br>

在第二个选项卡中打开此页面,您可以从一个选项卡与另一个选项卡(或世界各地的其他计算机)进行聊天.什么臭,你必须自己得到报价:

• 按OfferTab A中的按钮(仅限)并等待1-20秒,直到看到要约文本为止,
• 将提示文本从选项卡A复制粘贴到选项卡B,然后点击 Enter
• 将选项卡B中显示的答案文本复制粘贴到选项卡A,然后点击Enter.

您现在应该能够在没有服务器的选项卡之间聊天.

正如你所看到的,这是一个低于标准的体验,这就是为什么你需要一些基本的websocket服务器来传递提议/答案(以及如果你想快速连接发生的涓流冰候选人),以获得东西开始.一旦建立了连接,就可以使用数据通道进行一些额外的工作.