HTMLMediaElement: progress event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.
progress 事件在浏览器加载一个资源的时候周期性触发。
| Bubbles | No |
|---|---|
| Cancelable | No |
| Interface | Event |
| Event handler property | onprogress |
示例
>HTML
html
<div class="example"> <button type="button">Load video</button> <video controls width="250"></video> <div class="event-log"> <label>Event log:</label> <textarea readonly class="event-log-contents"></textarea> </div> </div> JavaScript
js
const loadVideo = document.querySelector("button"); const video = document.querySelector("video"); const eventLog = document.querySelector(".event-log-contents"); let source = null; function handleEvent(event) { eventLog.textContent = eventLog.textContent + `${event.type}\n`; } video.addEventListener("loadstart", handleEvent); video.addEventListener("progress", handleEvent); video.addEventListener("canplay", handleEvent); video.addEventListener("canplaythrough", handleEvent); loadVideo.addEventListener("click", () => { if (source) { document.location.reload(); } else { loadVideo.textContent = "Reset example"; source = document.createElement("source"); source.setAttribute( "src", "https://mdn.github.io/learning-area/html/multimedia-and-embedding/video-and-audio-content/rabbit320.mp4", ); source.setAttribute("type", "video/mp4"); video.appendChild(source); } }); 结果
规范
| Specification |
|---|
| HTML> # event-media-progress> |
| HTML> # handler-onprogress> |