目录

PdfView能否获取目录

问题现象

如何实现PDF预览的时候需要展示所有的目录？PdfView能否获取目录信息？

背景知识

PDF Kit（PDF服务）包含pdfService和PdfView组件。差异可以参照pdfService与PdfView能力比较。

解决方案

PDF展示目录其实是PDF书签功能，PdfView目前不支持该能力，需要使用pdfService添加、查询书签，两者具体区别参考pdfService与PdfView能力比较，使用示例如下：

  1. 本地PDF文件复制到沙箱目录，在项目rawfile文件夹下添加test.pdf（本示例以多页PDF为例）：
    public async copyFile(fileName: string): Promise<void> {
  return new Promise((resolve, reject) => {
    let filePath = this.context.filesDir + '/' + fileName;
    try {
      if (!fileIo.accessSync(filePath)) {
        this.context.resourceManager.getRawFileContent(fileName, (_err, value) => {
          try {
            let myBuffer: ArrayBufferLike = value.buffer;
            let file = fileIo.openSync(filePath, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE);
            let writeLen = fileIo.writeSync(file.fd, myBuffer);
            console.info(`write data to file succeed and size is:${writeLen}`);
            fileIo.closeSync(file);
            this.filePath = filePath;
            resolve();
          } catch (error) {
            reject(error);
          }
        });
      } else {
        this.filePath = filePath;
        resolve();
      }
    } catch (error) {
      reject(error);
    }
  });
}
  2. 给PDF增加书签（若原PDF自带书签可忽略步骤）：
    private createBookmarks() {
  // 创建书签
  let mark1: pdfService.Bookmark = this.pdfDocument.createBookmark();
  let mark2: pdfService.Bookmark = this.pdfDocument.createBookmark();
  // 设置书签的跳转信息
  let destInfo: pdfService.DestInfo = mark1.getDestInfo();
  destInfo.fitMode = pdfService.FitMode.FIT_MODE_XYZ;
  destInfo.pageIndex = 1;
  destInfo.left = 20;
  destInfo.top = 30;
  destInfo.zoom = 1.5;
  mark1.setDestInfo(destInfo);
  // 设置书签内容及样式
  let bookInfo: pdfService.BookmarkInfo = mark1.getBookmarkInfo();
  bookInfo.title = '这里是跳到第一页的书签';
  bookInfo.titleColor = 12;
  bookInfo.isBold = true;
  bookInfo.isItalic = true;
  mark1.setBookmarkInfo(bookInfo);
  // 把创建的书签插入到PDF页面
  this.pdfDocument.insertBookmark(mark1, null, 1);
  this.pdfDocument.insertBookmark(mark2, mark1, 1);
  // 设置保存文档沙箱路径并保存
  this.outPdfPath = this.context.filesDir + '/testAddBookmark.pdf';
  let result = this.pdfDocument.saveDocument(this.outPdfPath);
  hilog.info(0x0000, 'PdfPage', 'saveAddBookmark %{public}s!', result ? 'success' : 'fail');
}
  3. 完整示例如下：
    import { pdfService } from '@kit.PDFKit';
import { fileIo } from '@kit.CoreFileKit';
import { hilog } from '@kit.PerformanceAnalysisKit';

@Component
@Entry
struct PdfGetDirectory {
  @State filePath: string = '';
  @State outPdfPath: string = '';
  private pdfDocument: pdfService.PdfDocument = new pdfService.PdfDocument();
  private context = this.getUIContext().getHostContext() as Context;

  build() {
    Column() {
      Button('创建PDF书签')
        .width(200)
        .margin({ top: 100 })
        .onClick(async () => {
          await this.copyFile('test.pdf'); // 此处仅为示例，请开发者替换为实际使用的文件。
          let loadResult = this.pdfDocument.loadDocument(this.filePath, '');
          if (pdfService.ParseResult.PARSE_SUCCESS === loadResult) {
            // 创建书签
            this.createBookmarks();
          }
        });
      Button('查询PDF书签')
        .width(200)
        .margin({ top: 100 })
        .onClick(() => {
          // 确保加载的是保存了书签的文件
          let loadResult = this.pdfDocument.loadDocument(this.outPdfPath, '');
          if (pdfService.ParseResult.PARSE_SUCCESS === loadResult) {
            this.verifyBookmarks();
          } else {
            console.error('加载PDF文件失败: ' + loadResult);
          }
        });
    }
    .width('100%')
    .height('100%');
  }
  private createBookmarks() {
    // 创建书签
    let mark1: pdfService.Bookmark = this.pdfDocument.createBookmark();
    let mark2: pdfService.Bookmark = this.pdfDocument.createBookmark();
    // 设置书签的跳转信息
    let destInfo: pdfService.DestInfo = mark1.getDestInfo();
    destInfo.fitMode = pdfService.FitMode.FIT_MODE_XYZ;
    destInfo.pageIndex = 1;
    destInfo.left = 20;
    destInfo.top = 30;
    destInfo.zoom = 1.5;
    mark1.setDestInfo(destInfo);
    // 设置书签内容及样式
    let bookInfo: pdfService.BookmarkInfo = mark1.getBookmarkInfo();
    bookInfo.title = '这里是跳到第一页的书签';
    bookInfo.titleColor = 12;
    bookInfo.isBold = true;
    bookInfo.isItalic = true;
    mark1.setBookmarkInfo(bookInfo);
    // 把创建的书签插入到PDF页面
    this.pdfDocument.insertBookmark(mark1, null, 1);
    this.pdfDocument.insertBookmark(mark2, mark1, 1);
    // 设置保存文档沙箱路径并保存
    this.outPdfPath = this.context.filesDir + '/testAddBookmark.pdf';
    let result = this.pdfDocument.saveDocument(this.outPdfPath);
    hilog.info(0x0000, 'PdfPage', 'saveAddBookmark %{public}s!', result ? 'success' : 'fail');
  }
  private verifyBookmarks() {
    // 重新加载并验证书签
    let loadResult = this.pdfDocument.loadDocument(this.outPdfPath, '');
    if (pdfService.ParseResult.PARSE_SUCCESS === loadResult) {
      let rootBookmark = this.pdfDocument.getRootBookmarks();
      if (rootBookmark.length > 0) {
        console.info('验证书签: ' + JSON.stringify(rootBookmark[0].getBookmarkInfo()));
      } else {
        console.info('验证无书签');
      }
    }
  }
  public async copyFile(fileName: string): Promise<void> {
    return new Promise((resolve, reject) => {
      let filePath = this.context.filesDir + '/' + fileName;
      try {
        if (!fileIo.accessSync(filePath)) {
          this.context.resourceManager.getRawFileContent(fileName, (_err, value) => {
            try {
              let myBuffer: ArrayBufferLike = value.buffer;
              let file = fileIo.openSync(filePath, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE);
              let writeLen = fileIo.writeSync(file.fd, myBuffer);
              console.info(`write data to file succeed and size is:${writeLen}`);
              fileIo.closeSync(file);
              this.filePath = filePath;
              resolve();
            } catch (error) {
              reject(error);
            }
          });
        } else {
          this.filePath = filePath;
          resolve();
        }
      } catch (error) {
        reject(error);
      }
    });
  }
}

常见FAQ

Q：pdfService和PdfView一起使用对内存会有影响吗？

A：不会增加很多内存，如果想查询应用内存限制，可以参考hidebug.getAppMemoryLimit接口。