在国外找到一个在线手电筒按钮,可以借用浏览器,能够控制手机的相机闪光灯发出强光,达之手电筒效果,
但是,只有开启按钮,没有关闭按钮。
想请帮忙加多一个关闭按钮!
<button class="switch">Click to turn ON Flash Light</button>
<script>
//Test browser support
const SUPPORTS_MEDIA_DEVICES = 'mediaDevices' in navigator;
if (SUPPORTS_MEDIA_DEVICES) {
//Get the environment camera (usually the second one)
navigator.mediaDevices.enumerateDevices().then(devices => {
const cameras = devices.filter((device) => device.kind === 'videoinput');
if (cameras.length === 0) {
throw 'No camera found on this device.';
}
const camera = cameras[cameras.length - 1];
// Create stream and get video track
navigator.mediaDevices.getUserMedia({
video: {
deviceId: camera.deviceId,
facingMode: ['user', 'environment'],
height: {ideal: 1080},
width: {ideal: 1920}
}
}).then(stream => {
const track = stream.getVideoTracks()[0];
//Create image capture object and get camera capabilities
const imageCapture = new ImageCapture(track)
const photoCapabilities = imageCapture.getPhotoCapabilities().then(() => {
//todo: check if camera has a torch
//let there be light!
const btn = document.querySelector('.switch');
btn.addEventListener('click', function(){
track.applyConstraints({
advanced: [{torch: true}]
});
});
});
});
});
//The light will be on as long the track exists
}
</script>