想要获取一个pdf文件的页数，有多种实现方式。可以利用pdfjs，也可以利用PDFDocument：

// 方法一：利用文件的arrayBuffer
let arrayBuffer = await file.arrayBuffer();
const pdfDoc = await PDFDocument.load(arrayBuffer, { ignoreEncryption: true });
const pageCount =  pdfDoc.getPageCount();// 方法二：利用文件生成blob对象
const pdfObj = await PDFDocument.load(blob, { ignoreEncryption: true });
const pageCount = pdfObj.getPageCount();// 方法三：利用文件的在线预览地址
const byteString = atob(file.base64.split(',')[1]);
const mimeString = file.base64.split(',')[0].split(':')[1].split(';')[0];
const ab = new ArrayBuffer(byteString.length);
const ia = new Uint8Array(ab);
for (let i = 0; i < byteString.length; i++) {ia[i] = byteString.charCodeAt(i);
}const loadingTask = pdfjsLib.getDocument({data: ab,password: file.code || '',
});const pdfDocument = await loadingTask.promise;
const pageCount = pdfDocument.numPages;

如果是加密文件，想要使用pdfjs方式获取文件页数，需要提前给用户弹出密码框进行密码输入及验证，如何进行密码验证呢

（office文件暂时没有密码正确性验证的方式，因此只能校验是否是加密文件，而pdf文件可以校验出是否其他权限有无加密）

import { PDFDocument  } from 'pdf-lib';
import '@/assets/pdfjs/build/pdf.js'
import '@/assets/pdfjs/build/pdf.worker.js'
import * as XLSX from 'xlsx';
import JSZip from 'jszip';
import { gaEvent } from '@/utils/gtag'// 判断是否已加密
const checkIfFileEncrypted = async (file: any, isCloud: boolean) => {try {let arrayBuffer;if (isCloud) {const link = await getAccessLink(file.cloudId || file.file_id, file.name || file.file_name);const response = await fetch(link);if (!response.ok) throw new Error('Failed to fetch file');arrayBuffer = await response.arrayBuffer();} else {if(!file.base64) {arrayBuffer = await file.arrayBuffer();} else {const byteString = atob(file.base64.split(',')[1]);const mimeString = file.base64.split(',')[0].split(':')[1].split(';')[0];const ab = new ArrayBuffer(byteString.length);const ia = new Uint8Array(ab);for (let i = 0; i < byteString.length; i++) {ia[i] = byteString.charCodeAt(i);}// 创建 Blobconst blob = new Blob([ab], { type: mimeString });const fileObj = blobToFile(blob, file.name);arrayBuffer = await fileObj.arrayBuffer();}}if (file.type === 'application/pdf' || file.file_type === 'pdf' || file.name.endsWith('.pdf')) {// PDF 文件的加密检查const result = await checkPDFFileEncryption(arrayBuffer);return result.isEncrypted;} else if (file.type === 'application/vnd.openxmlformats-officedocument.wordprocessingml.document' ||file.type === 'application/msword' ||file.file_type === 'docx' ||file.file_type === 'doc') {// Word 文件的加密检查return checkWordFileEncryption(arrayBuffer);} else if (file.type === 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' ||file.type === 'application/vnd.ms-excel' ||file.file_type === 'xlsx' ||file.file_type === 'xls') {// Excel 文件的加密检查return checkExcelFileEncryption(arrayBuffer);} else if (file.type === 'application/vnd.openxmlformats-officedocument.presentationml.presentation' ||file.type === 'application/vnd.ms-powerpoint' ||file.file_type === 'pptx' ||file.file_type === 'ppt') {// PPT 文件的加密检查return checkPPTFileEncryption(arrayBuffer);} else {return false; // 默认不加密}} catch (error) {return false;}
};// PDF 文件加密检测
const checkPDFFileEncryption = async (arrayBuffer: any) => {try {const loadingTask = pdfjsLib.getDocument({ data: arrayBuffer });const pdfDoc = await loadingTask.promise;const permissions = await pdfDoc.getPermissions();if (permissions) {return {isEncrypted: false,hasOwnerPassword: true};}return {isEncrypted: false,hasOwnerPassword: false};} catch (error: any) {if (error.name === 'PasswordException') {return {isEncrypted: true,hasOwnerPassword: false};}return {isEncrypted: false,hasOwnerPassword: false};}
};// 验证 PDF 密码的函数
const verifyPDFPassword = async (file: any, password: string, isCode: boolean) => {try {let arrayBuffer;if (isCode) { // 云盘文件const link = await getAccessLink(file.cloudId || file.file_id, file.name || file.file_name);const response = await fetch(link);if (!response.ok) throw new Error('Failed to fetch file');arrayBuffer = await response.arrayBuffer();} else {arrayBuffer = await file.arrayBuffer();}const loadingTask = pdfjsLib.getDocument({data: arrayBuffer,password: password,});await loadingTask.promise;return true; // 密码正确} catch (error: any) {if (error.name === 'PasswordException') {return false; // 密码错误}return false; // 其他错误}
};// 提示用户输入密码的函数
const promptUserForPassword = async (file: any) => {return new Promise((resolve) => {EventBus.$emit('show-password-prompt', file, (action: any, password: string) => {resolve({ action, password });});});
};// Word 文件加密检测
const checkWordFileEncryption = async (arrayBuffer: any) => {try {const zip = await JSZip.loadAsync(arrayBuffer);if (zip.files['word/document.xml']) {return false; // 文件解压成功，说明未加密}} catch (error: any) {if (error.message.includes('End of data reached') ||error.message.includes('Corrupted zip') ||error.message.includes('Can\'t find end of central directory')) {return true; // 文件加密或损坏}}return false;
};// Excel 文件加密检测
const checkExcelFileEncryption = async (arrayBuffer: any) => {try {const workbook = XLSX.read(arrayBuffer, { type: 'array' });if (workbook.SheetNames.length > 0) {return false; // 文件解压成功，说明未加密}} catch (error: any) {if (error.message.includes('Encrypted') ||error.message.includes('File is password-protected')) {return true; // 文件加密}}return false;
};// PPT 文件加密检测
const checkPPTFileEncryption = async (arrayBuffer: any) => {try {const zip = await JSZip.loadAsync(arrayBuffer);if (zip.files['ppt/presentation.xml']) {return false; // 文件解压成功，说明未加密}} catch (error: any) {if (error.message.includes('Encrypted') ||error.message.includes('Can\'t find end of central directory')) {return true; // 文件加密}}return false;
};

通过以上方式即可成功拿到进行加密校验，下面是word、PPT、Excel格式文件获取文件页数的方式：

// 获取PDF文件页数
const getPDFPageCount = async (arrayBuffer, password) => {const loadingTask = pdfjsLib.getDocument({ data: arrayBuffer, password });const pdfDocument = await loadingTask.promise;return pdfDocument.numPages;
};// 获取Word文件页数
const getWordPageCount = async (arrayBuffer) => {try {const zip = await JSZip.loadAsync(arrayBuffer);if (zip.files['word/document.xml']) {// 解析 document.xml 获取页数（此处仅为示例，具体解析需要更复杂的处理）return 1; // Word文件页数暂时返回1}} catch (error) {console.error('Error processing Word file:', error);}return 1;
};// 获取Excel文件页数
const getExcelPageCount = async (arrayBuffer) => {try {const workbook = XLSX.read(arrayBuffer, { type: 'array' });// 以工作表的数量作为页数return workbook.SheetNames.length;} catch (error) {console.error('Error processing Excel file:', error);}return 1;
};// 获取PPT文件页数
const getPPTPageCount = async (arrayBuffer) => {try {const zip = await JSZip.loadAsync(arrayBuffer);if (zip.files['ppt/slides/']) {// 以幻灯片数量作为页数return Object.keys(zip.files['ppt/slides/']).length;}} catch (error) {console.error('Error processing PPT file:', error);}return 1;
};