svg转图片base64

 const svg = document.getElementById('svg'); //获取元素
// const s = new XMLSerializer().serializeToString(svg); //xml序列化
const src = `data:image/svg+xml;base64,${window.btoa(unescape(encodeURIComponent(svg)))}`; // base64转化
const img = new Image(); // 图片容器承载过渡
img.src = src;
img.onload = () => {
// 图片创建后再执行，转Base64过程
const canvas = document.createElement('canvas');
canvas.width = img.width;
canvas.height = img.height;
const context = canvas.getContext('2d');
context.drawImage(img, 0, 0);
const ImgBase64 = canvas.toDataURL('image/png');
console.log(ImgBase64, 'Svg 转 png');
}