--- title: 'HTMLMediaElement: progress イベント' slug: Web/API/HTMLMediaElement/progress_event tags: - API - Event - HTMLMediaElement - Reference - Web - progress - イベント translation_of: Web/API/HTMLMediaElement/progress_event ---
progress イベントは、ブラウザーがリソースを読み込むときに定期的に発生します。
| バブリング | なし |
|---|---|
| キャンセル可能 | いいえ |
| インターフェイス | {{domxref("Event")}} |
| イベントハンドラープロパティ | onprogress |
<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>
.event-log-contents {
width: 18rem;
height: 5rem;
border: 1px solid black;
margin: .2rem;
padding: .2rem;
}
.example {
display: grid;
grid-template-areas:
"button log"
"video log";
}
button {
grid-area: button;
width: 10rem;
margin: .5rem 0;
}
video {
grid-area: video;
}
.event-log {
grid-area: log;
}
.event-log>label {
display: block;
}
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://interactive-examples.mdn.mozilla.net/media/examples/flower.webm');
source.setAttribute('type', 'video/webm');
video.appendChild(source);
}
});
{{ EmbedLiveSample('Live_example', '100%', '200px') }}
| 仕様書 | 状態 |
|---|---|
| {{SpecName('HTML WHATWG', "media.html#event-media-progress", "progress media event")}} | {{Spec2('HTML WHATWG')}} |
| {{SpecName('HTML5 W3C', "embedded-content-0.html#event-media-progress", "progress media event")}} | {{Spec2('HTML5 W3C')}} |
{{Compat("api.HTMLMediaElement.progress_event")}}