js Base64 转化成图片格式

function dataURLtoFile(dataurl, filename = 'file') {

          let arr = dataurl.split(',')

          let mime = arr[0].match(/:(.*?);/)[1]

          let suffix = mime.split('/')[1]

          let bstr = atob(arr[1])

          let n = bstr.length

          let u8arr = new Uint8Array(n)

          while (n--) {

              u8arr[n] = bstr.charCodeAt(n)

          }

          return new File([u8arr], `${filename}.${suffix}`, {

              type: mime

          })

      }

      var base64Img = imgDataUrl // base64编码的图片

      var imgFile = dataURLtoFile(base64Img)

      console.log('imgFile====>', imgFile)