axios下载流文件，下载base64文件

request({
    url:url,
    method:‘post‘,
    data,
    responseType:‘blob‘
})

const blob = new Blob([res])
const fileName = ‘文件名，带后缀的‘
let a = document.createElement(‘a‘)
a.download = fileName
a.style.display = ‘none‘
a.href = URL.createObjectURL(blob)
document.body.appendChild(a)
a.click()
URL.revokeObjectURL(a.href)
document.body.removeChild(a)

let bstr = atob(base64数据)
let n = bstr.length;
let u8arr = new Uint8Array(n);
while(n--){
    u8arr[n] = bstr.charCodeAt(n)
}
let url = new Blob([u8arr],{type:‘doc‘})//这个type没啥用
let reader = new FileReader();
reader.readAsDataURL(url):
reader.onload=function(e){
    let a = document.createElement(‘a‘)
    a.download = 文件名
    a.href = e.target.result;
    document.body.appendChild(a)
    a.click()
    document.body.removeChild(a)
}