js下载blob二进制文件流 预览

1. 请求头中 要添加 responseType: 'arraybuffer'

// 下载 pdf
        const downloadFile = () => {
            let parameter = {  
                data: {
                    id: props.previewId,
                }
            };
            download(parameter).then((res?: any) => {
                downloadFileBlob(res, props.title, 'application/msword');
            });
        }
        // 下载方法
        function downloadFileBlob(data, name, type) {
            let url = window.URL.createObjectURL(new Blob([data], { type }));
            let link = document.createElement('a');
            link.style.display = 'none';
            link.href = url;
            link.setAttribute('download', name);
            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link); //下载完成移除元素
            window.URL.revokeObjectURL(url); //释放掉blob对象
        }
// 预览 
const getpdf = ()=>{
      allData.loading=true;
      let parameter = {  
          data: {
              id: props.previewId,
          }
      };
      download(parameter).then((res?: any) => {
            let url = window.URL.createObjectURL(new Blob([res], { type:     'application/pdf' }));
                pdfUrl.value = {
                    cMapUrl: './cmaps/',
                    url: url,
                };
                allData.loading=false;
            });
        }

 使用  vue-pdf-embed  组件

<vue-pdf-embed v-else annotation-layer text-layer :source="pdfUrl" :scale="1" :width="800" :height="800" />