HTMLMediaElement: loadstart Ereignis

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since Juli 2015.

Dasloadstart Ereignis wird ausgelöst, wenn der Browser begonnen hat, eine Ressource zu laden.

Syntax

Verwenden Sie den Ereignisnamen in Methoden wieaddEventListener() oder setzen Sie eine Ereignis-Handler-Eigenschaft.

addEventListener("loadstart", (event) => { })onloadstart = (event) => { }

Ereignistyp

Ein generischesEvent.

Beispiele

Live-Beispiel

HTML

html

<div>  <button type="button">Load video</button>  <video controls width="250"></video>  <div>    <label for="eventLog">Event log:</label>    <textarea readonly></textarea>  </div></div>

.event-log-contents {  width: 18rem;  height: 5rem;  border: 1px solid black;  margin: 0.2rem;  padding: 0.2rem;}.example {  display: grid;  grid-template-areas:    "button log"    "video  log";}button {  grid-area: button;  width: 10rem;  margin: 0.5rem 0;}video {  grid-area: video;}.event-log {  grid-area: log;}.event-log > label {  display: block;}

JavaScript

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 += `${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", "/shared-assets/videos/flower.webm");    source.setAttribute("type", "video/webm");    video.appendChild(source);  }});