vue 文件url转文件流下载方法

urlToBold(url){
        let http = url.split('?')[0];
        let file  = http.split('/');
        let fileName = file[file.length - 1];
        fetch(url).then(res => res.blob()).then(blob => { // 将链接地址字符内容转变成blob地址
          const aLink = document.createElement('a')
          aLink.href = URL.createObjectURL(blob)
          // 文件名字
          aLink.download = fileName;
          document.body.appendChild(aLink)
          aLink.click()
          aLink.remove();
        })
      },