vue---导出文件，通讯录为excel的文件流

 　　　　　　 let blob = new Blob([res], { type: ‘application/vnd.ms-excel‘ });
            let url = window.URL.createObjectURL(blob);
            var filename = ‘通讯录‘;
            let link = document.createElement(‘a‘)
            link.style.display = ‘none‘
            link.href = url
            link.setAttribute(‘download‘, filename + ‘.xls‘)
            document.body.appendChild(link)
            link.click()