js 图片下载 （图片链接转base64下载，兼容谷歌Chrome）

<script>let link = document.createElement('a');link.download = `123.jpg`; 	//下载的资源重命名getUrlBase64('http://localhost/456.jpg', 'jpg', function (base64Url) {link.href = base64Url;link.click();});/*** 通过图片链接获取base64* @param url   //图片链接* @param ext   //图片格式* @param callback  //回调函数，回调base64*/function getUrlBase64(url, ext, callback) {var canvas = document.createElement("canvas");   //创建canvas DOM元素var ctx = canvas.getContext("2d");var img = new Image;img.crossOrigin = 'Anonymous';img.src = url;img.onload = function () {canvas.height = img.height; //指定画板的高度,自定义canvas.width = img.width; //指定画板的宽度，自定义ctx.drawImage(img, 0, 0, img.height, img.width); //参数可自定义var dataURL = canvas.toDataURL("image/" + ext);callback.call(this, dataURL); //回掉函数获取Base64编码canvas = null;};}
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