带有ng2-pdfjs-viewer的PDF结构无效

时间:2020-09-14 20:25:28

标签: javascript angular ng2-pdfjs-viewer

我试图在ng2-pdfjs-viewer中加载PDF,但出现“无效的PDF结构,未定义的错误”。后端以Blob格式将数据返回给我,但是当我输入UI时,它会出现上述错误:

HTML代码:

  <div class="mlp-flex-container mlp-flex-container--relative mlp-flex-item">
    <div *ngIf="!showReport" class="informationMessage">Please Select a Trader</div>
    <ng2-pdfjs-viewer *ngIf="showReport" #pdfViewer class="pdfViewer"></ng2-pdfjs-viewer>
  </div>

JS代码:

  private async getDataAsync(message: ReportGroupMessage) {
    const rawData = await this.croDashboardPerformanceReportsDataService.getPerformanceReportsLocationDataAsync(message);
    this.pdfViewer.pdfSrc = rawData;
    this.pdfViewer.refresh();
  }

  public getPerformanceReportsLocationDataAsync(reportGroupMessage: ReportGroupMessage | any): Promise<any> {
    debugger
    const url = `Confidential URL`;
    return this.http.get(url, { responseType: 'blob' })
      .pipe(
        map((result: any) => {
          return result;
        })
      ).toPromise();
  }

有人可以帮忙吗?

1 个答案:

答案 0 :(得分:1)

从node.js api发送pdf文件作为我的有角前端的缓冲区时,我遇到了同样的问题。最后,我将文件作为base64发送到了前端。在那里,我将base64字符串转换为ArrayBuffer。

例如我的api路线:

const fs = require('fs');
const fsPromises = fs.promises;

router.get("/", async (req, res) => {
  try {
    // Set absolute path
    const fileAbsolutePath = req.query.fileAbsolutePath;
    // Read file as base64 string
    const base64Source = await fsPromises.readFile(fileAbsolutePath, { encoding: 'base64'});
    return res.status(200).send({ pdf: base64Source.toString('utf-8') });
  } catch (e) {
    logger.error("Error while sending the PDF File: ", e);
    return res.status(500).send(e.message);
  }
});

我的component.ts文件:

@ViewChild('pdfViewer') public pdfViewer;

getPDFSource(fileAbsolutePath: string): void {
    this.viewerService.getPDF(fileAbsolutePath).pipe(take(1)).subscribe(source => {
      // Convert base64 to ArrayBuffer
      const myBuffer = Uint8Array.from(atob(source.pdf), c => c.charCodeAt(0));
      // Set the source of the pdf viewer
      this.pdfViewer.pdfSrc = myBuffer;
      // Refresh the pdf viewer
      this.pdfViewer.refresh();
    });
  }

here所述,您可以将base64字符串转换为ArrayBuffer。
在.html文件中,将ng2-pdfjs-viewer定义为模板变量,以通过.ts文件中的viewchild访问查看器。

我的viewer.service.ts文件:

getPDF(fileAbsolutePath: string): Observable<any> {
    return this.http.get<any>(`${apiUrl}`?fileAbsolutePath=${fileAbsolutePath});
  }