Javascript で PDFのページ数を取得するだけの処理(PDF.js) - Qiita

function fToBase64Convert(file) { return new Promise((resolve, reject)=>{ const reader = new FileReader(); reader.onload = () => { resolve(reader.result); } reader.onerror = reject; reader.readAsArrayBuffer(file); }); } function getPdfPageNums(file){ return new Promise(async(resolve, reject)=>{ try{ pdfjsLib.GlobalWorkerOptions.workerSrc ="https://cdn.jsdelivr.net/npm/pdfjs-dist@2.7.570/build/pdf.