<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>base64轉pdf</title> <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script> <!-- <style> iframe { height: 800px; width: 800px } </style> --> </head> <body> <div> <a class="down" href=""></a> </div> <button onclick="myFunction()">download Img</button> <button onclick="myFunction2()">download pdf </button> </body> <script> function myFunction() { let base64 = 'data:image/png;base64,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'; function dataURLtoBlob(dataurl) { var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1], bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n); while (n--) { u8arr[n] = bstr.charCodeAt(n); } return new Blob([u8arr], { type: mime }); } //調用 let blob = dataURLtoBlob(base64); let link = document.createElement('a') link.download = 'abc.pdf' // 要下載的文件名 link.href = URL.createObjectURL(blob); // 觸發點擊 document.body.appendChild(link); link.click(); // 然后移除 document.body.removeChild(link); } /** * desc: base64對象轉blob文件對象 * @param urlData ：數據的base64對象 * @param type ：類型 png,pdf,doc,mp3等; * @returns {Blob}：Blob文件對象 */ function base64ToBlob(urlData, type) { let arr = urlData.split(','); let array = arr[0].match(/:(.*?);/); let mime = (array && array.length > 1 ? array[1] : type) || type; // 去掉url的頭，並轉化為byte let bytes = window.atob(arr[1]); // 處理異常,將ascii碼小於0的轉換為大於0 let ab = new ArrayBuffer(bytes.length); // 生成視圖（直接針對內存）：8位無符號整數，長度1個字節 let ia = new Uint8Array(ab); for (let i = 0; i < bytes.length; i++) { ia[i] = bytes.charCodeAt(i); } return new Blob([ab], { type: mime }); } /** * desc: 下載導出文件 * @param blob ：返回數據的blob對象或鏈接 * @param fileName ：下載后文件名標記 * @param fileType ：文件類 word(docx) excel(xlsx) ppt等 */ function downloadExportFile(blob, fileName, fileType) { let downloadElement = document.createElement('a'); let href = blob; if (typeof blob == 'string') { downloadElement.target = '_blank'; } else { href = window.URL.createObjectURL(blob); //創建下載的鏈接 } downloadElement.href = href; downloadElement.download = fileName + '.' + fileType; //下載后文件名 document.body.appendChild(downloadElement); downloadElement.click(); //觸發點擊下載 document.body.removeChild(downloadElement); //下載完成移除元素 if (typeof blob != 'string') { window.URL.revokeObjectURL(href); //釋放掉blob對象 } } /** * desc: base64轉文件並下載 * @param base64 {String} : base64數據 * @param fileType {String} : 要導出的文件類型png,pdf,doc,mp3等 * @param fileName {String} : 文件名 */ function downloadFile(base64, fileName, fileType) { let typeHeader = 'data:application/' + fileType + ';base64,' // 定義base64 頭部文件類型 let converedBase64 = typeHeader + base64; // 拼接最終的base64 let blob = base64ToBlob(converedBase64, fileType) // 轉成blob對象 downloadExportFile(blob, fileName, fileType) // 下載文件 } function myFunction2() { downloadFile("base64","123.pdf","pdf"); } </script> </html>