// 把图片链接转化成base64
    const convertimg2base64 = (img) => {
        const canvasEl = document.createElement('canvas');
        canvasEl.width = img.width;
        canvasEl.height = img.height;
        const ctx = canvasEl.getContext('2d');
        ctx.drawImage(img, 0, 0, img.width, img.height);
        const imgsuffix = img.src
            .match(/\.[^\\.]+$/)[0]
            .substring(1)
            .toLowerCase();
        return canvasEl.toDataURL(`image/${imgsuffix}`);
    };
    const tobase64 = (link, callback) => {
        const img = new Image();
        img.src = link;
        img.crossOrigin = 'anonymous';
        img.addEventListener('load', () => {
            const imgbase64 = convertimg2base64(img);
            callback(imgbase64);
        });
    };

使用：
detail?.avatar  = 'https://img2.baidu.com/it/u=3791594086,1804445139&fm=253&fmt=auto&app=138&f=JPEG?w=658&h=494'
  let detail['imgbase64'] = '';
  tobase64(detail?.avatar, (base64data) => {
            detail['imgbase64'] = base64data;
        });