語法
在諸如 addEventListener() 之類的方法中使用事件名稱,或設定事件處理程式屬性。
js
addEventListener("change", (event) => { })
onchange = (event) => { }
事件型別
一個通用的 Event。
示例
使用 addEventListener()
js
const videoElement = document.querySelector("video");
videoElement.audioTracks.addEventListener("change", (event) => {
console.log(`'${event.type}' event fired`);
});
// changing the value of `enabled` will trigger the `change` event
const toggleTrackButton = document.querySelector(".toggle-track");
toggleTrackButton.addEventListener("click", () => {
const track = videoElement.audioTracks[0];
track.enabled = !track.enabled;
});
使用 onchange 事件處理程式屬性
js
const videoElement = document.querySelector("video");
videoElement.audioTracks.onchange = (event) => {
console.log(`'${event.type}' event fired`);
};
// changing the value of `enabled` will trigger the `change` event
const toggleTrackButton = document.querySelector(".toggle-track");
toggleTrackButton.addEventListener("click", () => {
const track = videoElement.audioTracks[0];
track.enabled = !track.enabled;
});
規範
| 規範 |
|---|
| HTML # event-media-change |
| HTML # handler-tracklist-onchange |
瀏覽器相容性
載入中…
另見
- 相關事件:
addtrack,removetrack - 此
VideoTrackList上的事件目標:change - 媒體捕獲和流 API
- WebRTC API