RTCPeerConnection 接口代表一个由本地计算机到远端的WebRTC连接。该接口提供了创建，保持，监控，关闭连接的方法的实现
WebRTC在浏览器中的兼容性。参考：
var PeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
（其他请查看https://developer.mozilla.org/zh-CN/docs/Web/API/RTCPeerConnection）
构造函数：RTCPeerConnection.RTCPeerConnection() ，创建一个新的RTCPeerConnection对象。
/**
* Get the user IP throught the webkitRTCPeerConnection
* @param onNewIP {Function} listener function to expose the IP locally
* @return undefined
*/
function getUserIP(onNewIP) { // onNewIp - your listener function for new IPs
//compatibility for firefox and chrome
var myPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
var pc = new myPeerConnection({
iceServers: []
}),
noop = function() {},
localIPs = {},
ipRegex = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/g,
key;
function iterateIP(ip) {
if (!localIPs[ip]) onNewIP(ip);
localIPs[ip] = true;
}
//create a bogus data channel
pc.createDataChannel("");
// create offer and set local description
pc.createOffer().then(function(sdp) {
sdp.sdp.split('\n').forEach(function(line) {
if (line.indexOf('candidate') < 0) return;
line.match(ipRegex).forEach(iterateIP);
});
pc.setLocalDescription(sdp, noop, noop);
}).catch(function(reason) {
// An error occurred, so handle the failure to connect
});
//listen for candidate events
pc.onicecandidate = function(ice) {
if (!ice || !ice.candidate || !ice.candidate.candidate || !ice.candidate.candidate.match(ipRegex)) return;
ice.candidate.candidate.match(ipRegex).forEach(iterateIP);
};
}
// Usage
getUserIP(function(ip){
alert("Got IP! :" + ip);
});
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原文链接：https://www.cnblogs.com/zyh-club/p/11097418.html
