js实现调用摄像头拍照功能
<!DOCTYPE html>
<html lang="en">
<head>
<!-- 样式部分可以忽略 -->
<style>
* {
padding: 0;
margin: 0;
}
div {
width: 100vw;
height: 100vh;
display: flex;
justify-content: center;
align-items: center;
}
.btn {
width: 100px;
height: 50px;
border-radius: 10px;
background: #ff9900;
line-height: 50px;
text-align: center;
color: #fff;
box-shadow: 0 0 10px #999;
}
video, canvas {
width: 300px;
height: 300px;
border: 5px solid #000;
border-radius: 10px;
margin-left: 5px;
}
</style>
</head>
<body>
<div>
<div id="play" class="btn">开启摄像</div>
<div id="take" class="btn">拍照</div>
<video id="video"></video>
<!-- 尽量在canvas标签上设置宽高 -->
<canvas id="canvas" width="300px" height="300px"></canvas>
</div>
<script>
// 开启摄像
document.getElementById('play').onclick = () => {
let constraints = {
// video属性设置
video: {
width: 300,
height: 300
},
// audio属性设置
audio: true
}
navigator.mediaDevices.getUserMedia(constraints)
.then(mediaStream => {
// 成功返回promise对象，接收一个mediaStream参数与video标签进行对接
document.getElementById('video').srcObject = mediaStream
document.getElementById('video').play()
})
// 失败就失败了
}
// 拍照、canvas绘制
document.getElementById('take').onclick = () => {
let ctx = document.getElementById("canvas").getContext('2d')
ctx.drawImage(document.getElementById("video"), 0, 0, 300, 300)
}
</script>
</body>
</html>
