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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

When a web site or app using RTCPeerConnection receives a new ICE candidate from the remote peer over its signaling channel, it delivers the newly-received candidate to the browser's ICE agent by calling RTCPeerConnection.addIceCandidate() . This adds this new remote candidate to the RTCPeerConnection 's remote description, which describes the state of the remote end of the connection.

若 candidate parameter is missing or a value of null is given when calling addIceCandidate() , the added ICE candidate is an "end-of-candidates" indicator. The same is the case if the value of the specified object's candidate is either missing or an empty string ( "" ), it signals that all remote candidates have been delivered.

The end-of-candidates notification is transmitted to the remote peer using a candidate with an a-line value of end-of-candidates .

During negotiation, your app will likely receive many candidates which you'll deliver to the ICE agent in this way, allowing it to build up a list of potential connection methods. This is covered in more detail in the articles WebRTC connectivity and Signaling and video calling .

句法

aPromise = pc.addIceCandidate(candidate);
addIceCandidate(candidate, successCallback, failureCallback);  
					

参数

candidate 可选

An object conforming to the RTCIceCandidateInit dictionary, or an RTCIceCandidate object; the contents of the object should be constructed from a message received over the signaling channel, describing a newly received ICE candidate that's ready to be delivered to the local ICE agent.

若无 candidate object is specified, or its value is null , an end-of-candidates signal is sent to the remote peer using the end-of-candidates a-line, formatted simply like this:

a=end-of-candidates
						

Deprecated parameters

In older code and documentation, you may see a callback-based version of this function. This has been deprecated and its use is strongly discouraged. You should update any existing code to use the Promise -based version of addIceCandidate() instead. The parameters for this form of addIceCandidate() are described below, to aid in updating existing code.

successCallback

A function to be called when the ICE candidate has been successfully added. This function receives no input parameters and doesn't return a value.

failureCallback

A function to be called if attempting to add the ICE candidate fails. Receives as input a DOMException object describing why failure occurred.

返回值

A Promise which is fulfilled when the candidate has been successfully added to the remote peer's description by the ICE agent. The promise does not receive any input parameters.

异常

When an error occurs while attempting to add the ICE candidate, the Promise returned by this method is rejected, returning one of the errors below as the 名称 attribute in the specified DOMException object passed to the rejection handler.

TypeError

The specified candidate's sdpMid and sdpMLineIndex are both null .

InvalidStateError

RTCPeerConnection currently has no remote peer established ( remoteDescription is null ).

OperationError

This can happen for a number of reasons:

• The value specified for sdpMid 为非 null and doesn't match the media description ID of any media description included within the remoteDescription .
• The specified value of sdpMLineIndex is greater than or equal to the number of media descriptions included in the remote description.
• 指定 ufrag doesn't match the ufrag field in any of the remote descriptions being considered.
• One or more of the values in the candidate string are invalid or could not be parsed.
• Attempting to add the candidate fails for any reason.

范例

This code snippet shows how to signal ICE candidates across an arbitrary signaling channel.

// This example assumes that the other peer is using a signaling channel as follows:
//
// pc.onicecandidate = event => {
//   if (event.candidate) {
//     signalingChannel.send(JSON.stringify({ice: event.candidate})); // "ice" is arbitrary
//   } else {
//     // All ICE candidates have been sent
//   }
// }
signalingChannel.onmessage = receivedString => {
  const message = JSON.parse(receivedString);
  if (message.ice) {
    // A typical value of ice here might look something like this:
    //
    // {candidate: "candidate:0 1 UDP 2122154243 192.168.1.9 53421 typ host", sdpMid: "0", ...}
    //
    // Pass the whole thing to addIceCandidate:
    pc.addIceCandidate(message.ice).catch(e => {
      console.log("Failure during addIceCandidate(): " + e.name);
    });
  } else {
    // handle other things you might be signaling, like sdp
  }
}
						

The last candidate to be signaled this way by the remote peer will be a special candidate denoting end-of-candidates. Out of interest, end-of-candidates may be manually indicated as follows:

pc.addIceCandidate({candidate:''});
						

However, in most cases you won't need to look for this explicitly, since the events driving the RTCPeerConnection will deal with it for you, sending the appropriate events.

规范

规范	状态	注释
WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCPeerConnection.addIceCandidate()' in that specification.	候选推荐	最初的规范。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
addIceCandidate	Chrome 51 51 Promise-based version. 24	Edge 15	Firefox 22 22 Starting in Firefox 68, the candidate parameter is optional when calling addIceCandidate() 。 null value for candidate indicates no more candidates will be sent, while an empty candidate string indicates that no more candidates will be sent for the current generation of candidates.	IE No	Opera 43 43 Promise-based version. 不支持 37 — 43	Safari 11	WebView Android 51 51 Promise-based version. Yes	Chrome Android 51 51 Promise-based version. Yes	Firefox Android 44 44 Starting in Firefox 68, the candidate parameter is optional when calling addIceCandidate() 。 null value for candidate indicates no more candidates will be sent, while an empty candidate string indicates that no more candidates will be sent for the current generation of candidates.	Opera Android 43 43 Promise-based version. 不支持 37 — 43	Safari iOS Yes	Samsung Internet Android 6.0 6.0 Promise-based version and unprefixed. 不支持 5.0 — 6.0 Promise-based version.

图例

完整支持

完整支持

不支持

不支持

见实现注意事项。

另请参阅

• WebRTC API
• Signaling and video calling
• WebRTC architecture overview
• WebRTC connectivity
• Lifetime of a WebRTC session

元数据

• 最后修改： Jan 25, 2020

相关话题

1. WebRTC API
2. RTCPeerConnection
3. 构造函数

   1. RTCPeerConnection()
4. 特性

   1. canTrickleIceCandidates
   2. connectionState
   3. currentLocalDescription
   4. currentRemoteDescription
   5. getDefaultIceServers()
   6. iceConnectionState
   7. iceGatheringState
   8. localDescription
   9. onaddstream
   10. onconnectionstatechange
   11. ondatachannel
   12. onicecandidate
   13. oniceconnectionstatechange
   14. onicegatheringstatechange
   15. onidentityresult
   16. onidpassertionerror
   17. onidpvalidationerror
   18. onnegotiationneeded
   19. onpeeridentity
   20. onremovestream
   21. onsignalingstatechange
   22. ontrack
   23. peerIdentity
   24. pendingLocalDescription
   25. pendingRemoteDescription
   26. remoteDescription
   27. sctp
   28. signalingState
5. 方法

   1. addIceCandidate()
   2. addStream()
   3. addTrack()
   4. close()
   5. createAnswer()
   6. createDataChannel()
   7. createOffer()
   8. generateCertificate()
   9. getConfiguration()
   10. getIdentityAssertion()
   11. getReceivers()
   12. getSenders()
   13. getStats()
   14. getStreamById()
   15. getTransceivers()
   16. removeStream()
   17. removeTrack()
   18. restartIce()
   19. setConfiguration()
   20. setIdentityProvider()
   21. setLocalDescription()
   22. setRemoteDescription()
6. 事件

   1. addstream
   2. identityresult
   3. negotiationneeded
   4. removestream
   5. signalingstatechange
7. 继承：

   1. EventTarget
8. Related pages for WebRTC

   1. MediaDevices.getUserMedia()
   2. Navigator.mediaDevices
   3. RTCCertificate
   4. RTCDTMFSender
   5. RTCDTMFToneChangeEvent
   6. RTCDataChannel
   7. RTCDataChannelEvent
   8. RTCDtlsTransport
   9. RTCErrorEvent
   10. RTCIceCandidate
   11. RTCIceTransport
   12. RTCPeerConnectionIceErrorEvent
   13. RTCPeerConnectionIceEvent
   14. RTCRtpReceiver
   15. RTCRtpSender
   16. RTCRtpTransceiver
   17. RTCSctpTransport
   18. RTCSessionDescription
   19. RTCStatsEvent
   20. RTCStatsReport
   21. RTCTrackEvent