一、
接口请求设置为 responseType: ‘blob’
二、

export upload = data => {
	retrun request({
		url:' ',
		method:'post',
		resopnseType:'blob',
		data
	})
}

let file = this.fileCopy [0].raw;
var formData = new FormData();
formData.append('file',file)
upload(formData ).then( async res => {
     if (res.data.type === 'application/json'){
           //Blob.text()返回一个promise且包含blob所有内容的UTF-8格式的     USVString。
           let text = await res.data.text();
           let jsonText = await JSON.parse(text)
       }else{
         const blob = new Blob([res.data],{type:'application/octet-stream;charset=utf-8'})
         let link = document.createElement('a')
         link.style.display = 'none'
         let objectUrl = URL.createObjectURL(blob)
         link.href = objectUrl
         link.download = '模板.xlsx'
         link.click()
         URL.revokeObjectUrl(objectUrl)
       }
   })