Html5使用摄像头

Html

<div id="contentHolder">
        <video id="video" width="320" height="320" autoplay>
        </video>
        <button id="snap" style="display: none">
            拍照
        </button>
        <canvas style="display: none" id="canvas" width="320" height="320">
        </canvas>
    </div>
    <div>
        <input type="button" value="拍照" onclick="CatchCode()" /></div>

Js

//这段代 主要是获取摄像头的视频流并显示在Video 签中           
        window.addEventListener("DOMContentLoaded", function () {
            var canvas = document.getElementById("canvas"),
            context = canvas.getContext("2d"),
            video = document.getElementById("video"),
            videoObj = { "video": true },
            errBack = function (error) {
                console.log("Video capture error: ", error.code);
            };
            //navigator.getUserMedia这个写法在Opera中好像是navigator.getUserMedianow       
            if (navigator.getUserMedia) {
                navigator.getUserMedia(videoObj, function (stream) {
                    video.src = stream;
                    video.play();
                }, errBack);
            } else if (navigator.webkitGetUserMedia) {
                navigator.webkitGetUserMedia(videoObj, function (stream) {
                    video.src = window.webkitURL.createObjectURL(stream);
                    video.play();
                }, errBack);
            }
            //这个是拍照按钮的事件，          
            $("#snap").click(function () {
                context.drawImage(video, 0, 0, 320, 320);
                //CatchCode();           
            });
        }, false);

        //这个是 刷新上 图像的        
        function CatchCode() {
            //$("#snap").click();
            document.getElementById("canvas").getContext("2d").drawImage(video, 0, 0, 320, 320);
            //实际运用可不写，测试代 ， 为单击拍照按钮就获取了当前图像，有其他用途    
            var canvans = document.getElementById("canvas");
            //获取浏览器页面的画布对象                       
            //以下开始编 数据   
            var imgData = canvans.toDataURL();
            //将图像转换为base64数据
            var base64Data = imgData.substr(22);
            //在前端截取22位之后的字符串作为图像数据       
            //开始异步上             
            $.post("Html5UseCamera.aspx?action=upload", { "img": base64Data }, function (data, status) { }, "text");
        }      

　　C#

byte[] imgBytes = Convert.FromBase64String(Request.Form["img"]);
            Stream stream = new MemoryStream(imgBytes);
            System.Drawing.Image image = System.Drawing.Image.FromStream(stream);
            image.Save(Server.MapPath("~/") + Guid.NewGuid().ToString() + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);