HTML 5调用摄像头并进行拍照

来源：互联网发布：csgo fps优化参数编辑：程序博客网时间：2024/05/19 13:23

一般情况下，DOMContentLoaded事件要在window.onload之前执行，当DOM树构建完成的时候就会执行DOMContentLoaded事件，而window.onload是在页面载入完成的时候，才执行，这其中包括图片等元素。大多数时候我们只是想在DOM树构建完成后，绑定事件到元素，我们并不需要图片元素，加上有时候加载外域图片的速度非常缓慢。

<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title><style>video {border: 1px solid #ccc;display: block;margin: 0 0 20px 0;float:left;}#canvas {margin-top: 20px;border: 1px solid #ccc;display: block;}</style></head><body><video id="video" width="500" height="400" autoplay></video><canvas id="canvas" width="500" height="400"></canvas><button id="snap">拍照</button><script type="text/javascript">var context = canvas.getContext("2d");//当DOM树构建完成的时候就会执行DOMContentLoaded事件window.addEventListener("DOMContentLoaded", function() {//获得Canvas对象var canvas = document.getElementById("canvas");//获得video摄像头区域var video = document.getElementById("video");var videoObj = {"video" : true};var errBack = function(error) {console.log("Video capture error: ", error.code);};//获得摄像头并显示到video区域if (navigator.getUserMedia) { // Standardnavigator.getUserMedia(videoObj, function(stream) {video.src = stream;video.play();}, errBack);} else if (navigator.webkitGetUserMedia) { // WebKit-prefixednavigator.webkitGetUserMedia(videoObj, function(stream) {video.src = window.webkitURL.createObjectURL(stream);video.play();}, errBack);} else if (navigator.mozGetUserMedia) { // Firefox-prefixednavigator.mozGetUserMedia(videoObj, function(stream) {video.src = window.URL.createObjectURL(stream);video.play();}, errBack);}}, false);// 触发拍照动作document.getElementById("snap").addEventListener("click", function() {context.drawImage(video, 0, 0, 640, 480);});</script></body></html>

1 1