html2Canvas+JsPDF 导出pdf 无法显示网络图片

html2Canvas+JsPDF 导出pdf

问题：类似于下面着这种网络图片使用img导出的时候是空白的

https://gimg3.baidu.com/search/src=http%3A%2F%2Fpics4.baidu.com%2Ffeed%2F7e3e6709c93d70cf827fb2fda054500cb8a12bc9.jpeg%40f_auto%3Ftoken%3Dd97d3f0fd06e680e592584f8c7a24ac8&refer=http%3A%2F%2Fwww.baidu.com&app=2021&size=f360,240&n=0&g=0n&q=75&fmt=auto?sec=1690045200&t=e1a88c44b1b9907677400a079766e0bf

解决：将网络图片转成base64

转base64
let res = await this.getBase64Image('https://gimg3.baidu.com/search/src=http%3A%2F%2Fpics4.baidu.com%2Ffeed%2F7e3e6709c93d70cf827fb2fda054500cb8a12bc9.jpeg%40f_auto%3Ftoken%3Dd97d3f0fd06e680e592584f8c7a24ac8&refer=http%3A%2F%2Fwww.baidu.com&app=2021&size=f360,240&n=0&g=0n&q=75&fmt=auto?sec=1690045200&t=e1a88c44b1b9907677400a079766e0bf')
this.aaa = res

getBase64Image(src) {
      return new Promise(resolve => {
        const img = new Image()
        img.crossOrigin = ''
        img.src = src
        img.onload = function() {
          const canvas = document.createElement('canvas')
          canvas.width = img.width
          canvas.height = img.height
          const ctx = canvas.getContext('2d')
          ctx && ctx.drawImage(img, 0, 0, img.width, img.height)
          const ext = img.src.substring(img.src.lastIndexOf('.') + 1).toLowerCase()
          const dataURL = canvas.toDataURL('image/' + ext)
          resolve(dataURL)
        }
      })
    },

导出