François Beaufort
Karty, okna i ekrany można udostępniać na platformie internetowej za pomocą interfejsu Screen Capture API. Metoda getDisplayMedia() pozwala użytkownikowi wybrać ekran, który ma być rejestrowany jako strumień multimediów. Strumień można nagrać za pomocą interfejsu MediaRecorder API lub udostępnić innym osobom w sieci. Nagranie można zapisać w pliku lokalnym metodą showOpenFilePicker().
Poniższy przykład pokazuje, jak zarejestrować ekran użytkownika w formacie WebM, wyświetlić jego podgląd lokalnie na tej samej stronie i zapisać nagranie w jego systemie plików.
let stream;
let recorder;
shareScreenButton.addEventListener("click", async () => {
// Prompt the user to share their screen.
stream = await navigator.mediaDevices.getDisplayMedia();
recorder = new MediaRecorder(stream);
// Preview the screen locally.
video.srcObject = stream;
});
stopShareScreenButton.addEventListener("click", () => {
// Stop the stream.
stream.getTracks().forEach(track => track.stop());
video.srcObject = null;
});
startRecordButton.addEventListener("click", async () => {
// For the sake of more legible code, this sample only uses the
// `showSaveFilePicker()` method. In production, you need to
// cater for browsers that don't support this method, as
// outlined in https://web.dev/patterns/files/save-a-file/.
// Prompt the user to choose where to save the recording file.
const suggestedName = "screen-recording.webm";
const handle = await window.showSaveFilePicker({ suggestedName });
const writable = await handle.createWritable();
// Start recording.
recorder.start();
recorder.addEventListener("dataavailable", async (event) => {
// Write chunks to the file.
await writable.write(event.data);
if (recorder.state === "inactive") {
// Close the file when the recording stops.
await writable.close();
}
});
});
stopRecordButton.addEventListener("click", () => {
// Stop the recording.
recorder.stop();
});
Obsługiwane przeglądarki
MediaDevices.getDisplayMedia()
Interfejs API MediaRecorder
Funkcja showSaveFilePicker() interfejsu File System Access API
Więcej informacji
- Specyfikacja zrzutu ekranu W3C
- Specyfikacja nagrywania W3C MediaStream
- Specyfikacja dostępu do systemu plików WICG
Pokaz
HTML
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link
rel="icon"
href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🖥️</text></svg>"
/>
<title>How to record the user's screen</title>
</head>
<body>
<h1>How to record the user's screen</h1>
<button id="startShareScreenButton">Start sharing screen</button>
<button id="stopShareScreenButton" disabled>Stop sharing screen</button>
<button id="startRecordButton" disabled>Start recording</button>
<button id="stopRecordButton" disabled>Stop recording</button>
<video autoplay muted playsinline></video>
<pre id="logs"></pre>
</body>
</html>CSS
:root {
color-scheme: dark light;
}
html {
box-sizing: border-box;
}
*,
*:before,
*:after {
box-sizing: inherit;
}
body {
margin: 1rem;
font-family: system-ui, sans-serif;
}
button {
display: block;
margin-bottom: 4px;
}
video {
display: block;
margin-top: 10px;
max-width: 100%;
background: black;
max-height: 480px;
}
pre {
color: red;
white-space: pre-line;
}
JS
const video = document.querySelector('video');
const startShareScreenButton = document.querySelector('#startShareScreenButton');
const stopShareScreenButton = document.querySelector('#stopShareScreenButton');
const startRecordButton = document.querySelector('#startRecordButton');
const stopRecordButton = document.querySelector('#stopRecordButton');
let stream;
let recorder;
startShareScreenButton.addEventListener("click", async () => {
// Prompt the user to share their screen.
stream = await navigator.mediaDevices.getDisplayMedia();
recorder = new MediaRecorder(stream);
// Preview the screen locally.
video.srcObject = stream;
startRecordButton.disabled = false;
stopShareScreenButton.disabled = false;
log("Your screen is being shared.");
});
stopShareScreenButton.addEventListener("click", () => {
// Stop the stream.
stream.getTracks().forEach(track => track.stop());
video.srcObject = null;
stopShareScreenButton.disabled = true;
startRecordButton.disabled = true;
stopRecordButton.disabled = true;
log("Your screen is not shared anymore.");
});
startRecordButton.addEventListener("click", async () => {
// For the sake of more legible code, this sample only uses the
// `showSaveFilePicker()` method. In production, you need to
// cater for browsers that don't support this method, as
// outlined in https://web.dev/patterns/files/save-a-file/.
// Prompt the user to choose where to save the recording file.
const suggestedName = "screen-recording.webm";
const handle = await window.showSaveFilePicker({ suggestedName });
const writable = await handle.createWritable();
// Start recording.
recorder.start();
recorder.addEventListener("dataavailable", async (event) => {
// Write chunks to the file.
await writable.write(event.data);
if (recorder.state === "inactive") {
// Close the file when the recording stops.
await writable.close();
}
});
stopRecordButton.disabled = false;
log("Your screen is being recorded locally.");
});
stopRecordButton.addEventListener("click", () => {
// Stop the recording.
recorder.stop();
stopRecordButton.disabled = true;
log("Your screen has been successfully recorded locally.");
});