The statechange event of the MIDIPort interface is fired when a port changes from open to closed, or closed to open.

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("statechange", (event) => {});

onstatechange = (event) => {};

A MIDIConnectionEvent. Inherits from Event.

MIDIConnectionEvent.port Read only

Returns a reference to a MIDIPort instance for a port that has been connected or disconnected.

In the following example the current MIDIPort.state is logged each time it changes.

port.onstatechange = (event) => {
  console.log(port.state);
};