RTCPeerConnection: connectionstatechange event - Web APIs 编辑

The connectionstatechange event is sent to the ontrack event handler on an RTCPeerConnection object after a new track has been added to an RTCRtpReceiver which is part of the connection. The new connection state can be found in connectionState, and is one of the strings in the RTCPeerConnectionState enumerated type.

Examples

For an RTCPeerConnection, pc, this example sets up a handler for connectionstatechange messages to handle changes to the connectivity of the WebRTC session. It calls an app-defined function called setOnlineStatus() to update a status display.

pc.onconnectionstatechange = ev => {
  switch(pc.connectionState) {
    case "new":
    case "checking":
      setOnlineStatus("Connecting...");
      break;
    case "connected":
      setOnlineStatus("Online");
      break;
    case "disconnected":
      setOnlineStatus("Disconnecting...");
      break;
    case "closed":
      setOnlineStatus("Offline");
      break;
    case "failed":
      setOnlineStatus("Error");
      break;
    default:
      setOnlineStatus("Unknown");
      break;
  }
}

You can also create a handler for connectionstatechange by using addEventListener():

pc.addEventListener("connectionstatechange", ev => {
  switch(pc.connectionState) {
    /* ... */
  }
}, false);

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• WebRTC API
• WebRTC connectivity
• Lifetime of a WebRTC session
• RTCPeerConnectionState