js生成word中图片处理方法

function changeImgToDataurl(){
 var charImg = document.all("exportdom").getElementsByTagName("img"); 
 var imgURLs = ""; 
 for (var i = 0; i < charImg.length; i++) { 
   var imgURL = charImg[i].currentSrc; 
   getBase64(imgURL,charImg[i]);
 } 
}
function getBase64(url,charImg){
  var Img = new Image();
  Img.crossOrigin = "Anonymous";//跨域必须使用，且后台也得设置允许跨域
  dataURL='';
  Img.src=url;
  Img.onload=function(){ //要先确保图片完整获取到，这是个异步事件
   var canvas = document.createElement("canvas"), //创建canvas元素
   width=Img.width, //确保canvas的尺寸和图片一样
   height=Img.height;
   canvas.width=width;
   canvas.height=height;
   canvas.getContext("2d").drawImage(Img,0,0,width,height); //将图片绘制到canvas中
   dataURL=canvas.toDataURL('image/jpg'); //转换图片为dataURL
   condataurl?condataurl(dataURL,charImg):null; //调用回调函数
  };
} 
function condataurl(dataURL,charImg){
 charImg.src=dataURL;
 //console.log(charImg);
}