axios 的responseType 设置了，但是还是无法下载

Question

Answer 1

需要服务端读取文件并设置 Content-Type: "application/octet-stream" 响应头，以express为例：

// 这里以express举例
const fs = require('fs')
const express = require('express')
const bodyParser = require('body-parser')

const app = express()
app.use(bodyParser.urlencoded({extended: false}))
app.use(bodyParser.json())

// 以post提交举例
app.post('/info/download', function(req, res) {
    const filePath = './file/测试.jpeg'
    const fileName = '测试.jpeg'
    // 设置content-type
    // content-disposition用于处理文件名为中文的情况
    res.set({
        'content-type': 'application/octet-stream',
        'content-disposition': 'attachment;filename=' + encodeURI(fileName)
    })

    fs.createReadStream(filePath).pipe(res)
})

app.listen(3000)

Answer 2

先排查单独将url打开至浏览器，能否自动下载文件。给你个例子参考

//data
 downloadImgSrc:'https://i.picsum.photos/id/452/400/300.jpg?hmac=0-o_NOka_K6sQ_sUD84nxkExoDk3Bc0Qi7Y541CQZEs'
//methods
downloadImg() {
      axios({
        url: this.downloadImgSrc, //URL,根据实际情况来
        method: "get",
        responseType: "blob"
      }).then(function (response) {
        const link = document.createElement("a");
        let blob = new Blob([response.data], { type: response.data.type });
        let url = URL.createObjectURL(blob);
        link.href = url;
        link.download = `实际需要的文件名.${response.data.type.split('/')[1]}`;
        link.click();
        document.body.removeChild(link);
      });
    }