图片转base64

    <script>
        /**图片地址转base64 */
        function getBase64(url, callback) {
            const Img = new Image();
            let dataURL = '';
            Img.src = url + '?v=' + Math.random();
            Img.setAttribute('crossOrigin', 'Anonymous');
            Img.onload = function () {
                const canvas = document.createElement('canvas');
                width = Img.width;
                height = Img.height;
                canvas.width = width;
                canvas.height = height;
                canvas.getContext('2d').drawImage(Img, 0, 0, width, height);
                dataURL = canvas.toDataURL('png');
                return callback ? callback(dataURL) : null;
            }
        }

        function fn(dataURL) {
            console.log('dataURL', dataURL)
        }
        getBase64('https://pics2.baidu.com/feed/a9d3fd1f4134970a26dd673042e657c2a7865d3d.png?token=1768dc88f831385dff7814254317c370', fn)
    </script>