使用javascript实现电脑摄像头的打开和截图的功能，供大家参考，具体内容如下
<!DOCTYPE html><html><head><meta charset="UTF-8"><title>摄像头调用实例</title><script type="text/javascript" src="jquery-3.2.1.min.js"></script><script type="text/javascript"> var video, mediaStreamTrack, canvas;//声明全局变量 //打开摄像头 function dk() { video = document.getElementById("v1"); var videoObj = { "video" : true }; var errBack = function(error) { console.log("Video capture error: ", error.code); }; //根据浏览器的不同选取不同的支持 if (navigator.getUserMedia) { // Standarda navigator.getUserMedia(videoObj, function(stream) { mediaStreamTrack = typeof stream.stop === 'function' ? stream : stream.getTracks()[1]; video.src = stream;//获取摄像头抓取的到字节流 video.play();//实时播放摄像头 }, errBack); } else if (navigator.webkitGetUserMedia) { // WebKit-prefixed navigator.webkitGetUserMedia(videoObj, function(stream) { mediaStreamTrack = typeof stream.stop === 'function' ? stream : stream.getTracks()[1]; video.src = window.webkitURL.createObjectURL(stream); video.play(); }, errBack); } else if (navigator.mozGetUserMedia) { // Firefox-prefixed navigator.mozGetUserMedia(videoObj, function(stream) { mediaStreamTrack = typeof stream.stop === 'function' ? stream : stream.getTracks()[1]; video.src = window.URL.createObjectURL(stream); video.play(); }, errBack); } } //截图 function jq() { canvas = document.getElementById("c1"); var context = canvas.getContext("2d"); //将视频当前的页面转换为图片，显示到画板中 context.drawImage(video, 0, 0, 200, 202); //把canvas图像转为img图片 /* var src = canvas.toDataURL("image/jpeg"); createImg(src); */ } //关闭摄像头 function gb() { mediaStreamTrack.stop(); } //生成图片 /* function createImg(src) { var dv = document.getElementById("dv1"); var img = document.createElement("img"); img.setAttribute("src", src); img.setAttribute("width", 205); img.setAttribute("height", 205); dv.appendChild(img); } */ //上传 /* function sc() { $.post('TestServlet', { "img" : canvas.toDataURL().substr(22) }, function(data, status) { alert(status != "success" ? "图片处理出错！" : data == "yes" ? "图片上传完成！" : data); }); } */</script><style type="text/css">input[type="button"]{border: 1px solid red;}</style></head><body> <div> <input type="button" value="打开" onclick="dk()"> <input type="button" value="截取图像" onclick="jq()"> <input type="button" value="关闭" onclick="gb()"> </div> <div> <!--视频 --> <video width="200px" height="200px" ></video> <br /> <!--画板 --> <canvas ></canvas> <br /> </div> <!--记录每次截图的结果 --> <!-- <div ></div> --></body></html>
