为了使用html实时拍照，代替选取图片提高使用效率，开发此功能，开发过程记录以作后期方便使用
流程
摄像头拍照.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div>
<video id="video"></video>
<canvas id="canvas"></canvas>
<!-- <canvas id="canvas" style="display: none"></canvas>-->
<button onclick="getPhoto()">拍照</button>
<script>
const width = 480;
const height = 320;
const video = document.getElementById('video');
//拍照
function getPhoto(){
//访问摄像头
if (navigator.mediaDevices.getUserMedia || navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia) {
//调用用户媒体设备, 访问摄像头
getUserMedia({video: {width: width, height: height}}, success, error);
} else {
alert('不支持访问用户媒体');
}
}
//访问用户媒体设备的兼容方法
function getUserMedia(constraints, success, error) {
if (navigator.mediaDevices.getUserMedia) {
//最新的标准API
navigator.mediaDevices.getUserMedia(constraints).then(success).catch(error);
} else if (navigator.webkitGetUserMedia) {
//webkit核心浏览器
navigator.webkitGetUserMedia(constraints, success, error)
} else if (navigator.mozGetUserMedia) {
//firfox浏览器
navigator.mozGetUserMedia(constraints, success, error);
} else if (navigator.getUserMedia) {
//旧版API
navigator.getUserMedia(constraints, success, error);
}
}
//成功回调
function success(stream) {
console.log('成功');
//兼容webkit核心浏览器
// const CompatibleURL = window.URL || window.webkitURL;
//将视频流设置为video元素的源
// video.src = CompatibleURL.createObjectURL(stream);
video.srcObject = stream;
video.play();
setInterval(drawCanvasImage, 10)
}
//失败回调
function error(error) {
console.log('失败');
console.log("访问用户媒体设备失败", error);
}
function drawCanvasImage() {
const canvas = document.getElementById('canvas');
canvas.width = width;
canvas.height = height;
const context = canvas.getContext('2d');
context.drawImage(video, 0, 0, width, height, 0, 0, width, height);
//获取图片，数据格式为base64
const imageData = canvas.toDataURL("image/png");
console.log(imageData +'\n')
}
</script>
</div>
</body>
</html>
根据图片url 获取图片文件.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>
</head>
<body>
<img/>
</body>
<script>
function getImageFileFromUrl(url, imageName,callback) {
// imageName一定要带上后缀
var blob = null;
var xhr = new XMLHttpRequest();
xhr.open("GET", url);
xhr.setRequestHeader('Accept', 'image/jpeg');
xhr.responseType = "blob";
xhr.onload = () => {
if (xhr.status == 200) {
blob = xhr.response;
let imgFile = new File([blob], imageName, {type: 'image/jpeg'});
console.log(imgFile)
callback.call(this,imgFile);
}};
xhr.send();
}
$(function () {
getImageFileFromUrl('https://dss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=4085579248,162891217&fm=15&gp=0.jpg','testFile.jpg',function(file){
debugger
console.log(file)
var r = new FileReader()
r.readAsDataURL(file)
r.onload = function (e) {
var base64 = e.target.result;
$("img").attr('src', base64);
}
});
})
</script>
</html>
