var CameraInit=(function(window,document,undefined){functionMyCamera(videoDom,canvasDom) {this.mediaOpts ={

audio:false,

video:true,

video: { facingMode:"environment"} //或者 "user"

//video: { width: 1280, height: 720 }

//video: { facingMode: { exact: "environment" } }// 或者 "user"

}this.video=videoDom;this.canvas1=canvasDom;this.context1 = this.canvas1.getContext('2d');this.mediaStreamTrack = null;this.checkEnvironment();

}

MyCamera.prototype={

checkEnvironment:function() {

window.URL= (window.URL || window.webkitURL || window.mozURL ||window.msURL);if (navigator.mediaDevices ===undefined) {

navigator.mediaDevices={};

}if (navigator.mediaDevices.getUserMedia ===undefined) {

navigator.mediaDevices.getUserMedia= function(constraints) {var getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia ||navigator.msGetUserMedia;if (!getUserMedia) {return Promise.reject(new Error('getUserMedia is not implemented in this browser'));

}return new Promise(function(resolve, reject) {

getUserMedia.call(navigator, constraints, resolve, reject);

});

}

}

},//回调

successFunc: function(stream) {this.mediaStreamTrack =stream;this.video = document.querySelector('video');if ("srcObject" in this.video) {this.video.srcObject =stream

}else{this.video.src = window.URL && window.URL.createObjectURL(stream) ||stream

}this.video.play();

},

errorFunc:function(err) {

alert(err.name);

},//正式启动摄像头

openMedia: function(){

navigator.mediaDevices.getUserMedia(this.mediaOpts).then(this.successFunc.bind(this)).catch(this.errorFunc);

},//关闭摄像头

closeMedia: function(){var that=this;

that.mediaStreamTrack.getVideoTracks().forEach(function(track) {

track.stop();

that.context1.clearRect(0, 0,that.context1.width, that.context1.height);//清除画布

});

},//截取视频并转为图片

drawMediaAndToImg: function(){this.canvas1.setAttribute("width", this.video.videoWidth);this.canvas1.setAttribute("height", this.video.videoHeight);this.context1.drawImage(this.video, 0, 0, this.video.videoWidth, this.video.videoHeight);//显示在canvas中

var image = newImage();

image.src= this.canvas1.toDataURL('image/png')var imageWarp = document.getElementById("imageWarp");if(imageWarp.hasChildNodes()) {

document.getElementById("imageWarp").replaceChild(image, imageWarp.firstChild);

}else{

document.getElementById("imageWarp").appendChild(image);

}

},

};returnMyCamera;

})(window,document)