最近出差开了好多发票，写了一个pdf合并网站，用于把多张发票pdf合并成一张，方便打印
使用pdf-lib这个库实现的pdf合并功能，预览使用的是浏览器自身查看pdf功能
源码
<!DOCTYPE html>
<html>
<head>
<title>PDF合并</title>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/pdf-lib.min.js"></script>
</head>
<body>
<input type="file" id="fileInput" multiple />
<button onclick="previewMergePDF()">预览合并的PDF</button>
<button onclick="downloadMergePDF()">下载合并的PDF</button>
<script>
async function previewMergePDF() {
const fileInput = document.getElementById("fileInput");
const files = fileInput.files;
if (files.length < 2) {
alert("请至少选择两个PDF文件进行合并！");
return;
}
// 创建一个新的PDF文档
const mergedPdf = await PDFLib.PDFDocument.create();
// 遍历选择的每个文件
for (let i = 0; i < files.length; i++) {
const file = files[i];
const reader = new FileReader();
// 读取文件内容
const fileContents = await new Promise((resolve, reject) => {
reader.onload = function (event) {
resolve(event.target.result);
};
reader.onerror = function (event) {
reject(new Error("文件读取错误。"));
};
reader.readAsArrayBuffer(file);
});
// 将PDF文件添加到合并的PDF文档中
const pdf = await PDFLib.PDFDocument.load(fileContents);
const copiedPages = await mergedPdf.copyPages(
pdf,
pdf.getPageIndices()
);
copiedPages.forEach((page) => {
mergedPdf.addPage(page);
});
}
// 使用浏览器自带预览功能，预览合并后的PDF
const mergedPdfBytes = await mergedPdf.save();
const mergedPdfBlob = new Blob([mergedPdfBytes], {
type: "application/pdf",
});
const fileURL = URL.createObjectURL(mergedPdfBlob);
window.open(fileURL);
}
async function downloadMergePDF() {
const fileInput = document.getElementById("fileInput");
const files = fileInput.files;
if (files.length < 2) {
alert("请至少选择两个PDF文件进行合并！");
return;
}
const mergedPdf = await PDFLib.PDFDocument.create();
for (let i = 0; i < files.length; i++) {
const file = files[i];
const reader = new FileReader();
const fileContents = await new Promise((resolve, reject) => {
reader.onload = function (event) {
resolve(event.target.result);
};
reader.onerror = function (event) {
reject(new Error("文件读取错误。"));
};
reader.readAsArrayBuffer(file);
});
const pdf = await PDFLib.PDFDocument.load(fileContents);
const copiedPages = await mergedPdf.copyPages(
pdf,
pdf.getPageIndices()
);
copiedPages.forEach((page) => {
mergedPdf.addPage(page);
});
}
const mergedPdfFile = await mergedPdf.saveAsBase64();
const downloadLink = document.createElement("a");
downloadLink.href = "data:application/pdf;base64," + mergedPdfFile;
downloadLink.download = "merged.pdf";
downloadLink.click();
}
</script>
</body>
</html>