##1

import download from 'downloadjs'
//这个res是后台返回的文件流
download((new Blob([res])), 'contract.pdf', 'application/pdf')

方法2 a标签下载

 let pdfContent = res;const blob = new Blob([pdfContent], { type: "application/pdf"});const url = window.URL.createObjectURL(blob);// 创建a标签并设置下载属性const a = document.createElement("a");a.style.display = "none";a.href = url;a.download = "downloaded_file.pdf";// 将a标签添加到页面中并触发点击事件document.body.appendChild(a);a.click();// 释放URL对象window.URL.revokeObjectURL(url);