有没有办法在pdf.js中合并PDF文件？

Question

嗯，我想现有的PDF文件在HTML5中使用pdf.js结合，生成一个PDF从他们的

这是可能的，我怎么能做到这一点？

Answer 1

合并多个文稿和仅显示他们作为一个与pdf.js是容易实现 - 我只是砍死基于一个简单的prev/next viewer的例子，Mozilla浏览器在他们的仓库提供了下面的例子。

// If absolute URL from the remote server is provided, configure the CORS 
 
    // header on that server. 
 
    // 
 
    var urls = [ 
 
     'http://mozilla.github.io/pdf.js/web/compressed.tracemonkey-pldi-09.pdf', 
 
     'http://mozilla.github.io/pdf.js/web/compressed.tracemonkey-pldi-09.pdf' 
 
    ]; 
 

 
    // Disable workers to avoid yet another cross-origin issue (workers need 
 
    // the URL of the script to be loaded, and dynamically loading a cross-origin 
 
    // script does not work). 
 
    // 
 
    // PDFJS.disableWorker = true; 
 

 
    // In cases when the pdf.worker.js is located at the different folder than the 
 
    // pdf.js's one, or the pdf.js is executed via eval(), the workerSrc property 
 
    // shall be specified. 
 
    // 
 
    // PDFJS.workerSrc = 'pdf.worker.js'; 
 

 
    /** 
 
    * @typedef {Object} PageInfo 
 
    * @property {number} documentIndex 
 
    * @property {number} pageNumber 
 
    */ 
 

 
var pdfDocs = [], 
 
    /** 
 
    * @property {PageInfo} 
 
    */ 
 
    current = {}, 
 
    totalPageCount = 0, 
 
    pageNum = 1, 
 
    pageRendering = false, 
 
    pageNumPending = null, 
 
    scale = 0.8, 
 
    canvas = document.getElementById('the-canvas'), 
 
    ctx = canvas.getContext('2d'); 
 

 
/** 
 
* Get page info from document, resize canvas accordingly, and render page. 
 
* @param num Page number. 
 
*/ 
 
function renderPage(num) { 
 
    pageRendering = true; 
 
    current = getPageInfo(num); 
 
    // Using promise to fetch the page 
 
    pdfDocs[current.documentIndex] 
 
    .getPage(current.pageNumber).then(function (page) { 
 
     var viewport = page.getViewport(scale); 
 
     canvas.height = viewport.height; 
 
     canvas.width = viewport.width; 
 

 
     // Render PDF page into canvas context 
 
     var renderContext = { 
 
      canvasContext: ctx, 
 
      viewport: viewport 
 
     }; 
 
     var renderTask = page.render(renderContext); 
 

 
     // Wait for rendering to finish 
 
     renderTask.promise.then(function() { 
 
      pageRendering = false; 
 
      if (pageNumPending !== null) { 
 
       // New page rendering is pending 
 
       renderPage(pageNumPending); 
 
       pageNumPending = null; 
 
      } 
 
     }); 
 
    }); 
 

 
    // Update page counters 
 
    document.getElementById('page_num').textContent = pageNum; 
 
} 
 

 
/** 
 
* If another page rendering in progress, waits until the rendering is 
 
* finised. Otherwise, executes rendering immediately. 
 
*/ 
 
function queueRenderPage(num) { 
 
    if (pageRendering) { 
 
     pageNumPending = num; 
 
    } else { 
 
     renderPage(num); 
 
    } 
 
} 
 

 
/** 
 
* Displays previous page. 
 
*/ 
 
function onPrevPage() { 
 
    if (pageNum <= 1) { 
 
     return; 
 
    } 
 
    pageNum--; 
 
    queueRenderPage(pageNum); 
 
} 
 
document.getElementById('prev').addEventListener('click', onPrevPage); 
 

 
/** 
 
* Displays next page. 
 
*/ 
 
function onNextPage() { 
 
    if (pageNum >= totalPageCount && current.documentIndex + 1 === pdfDocs.length) { 
 
     return; 
 
    } 
 
    
 
    pageNum++; 
 
    queueRenderPage(pageNum); 
 
} 
 
document.getElementById('next').addEventListener('click', onNextPage); 
 

 
/** 
 
* @returns PageNumber 
 
*/ 
 
function getPageInfo (num) { 
 
    var totalPageCount = 0; 
 
    for (var docIdx = 0; docIdx < pdfDocs.length; docIdx++) { 
 
     
 
     totalPageCount += pdfDocs[docIdx].numPages; 
 
     if (num <= totalPageCount) { 
 
      return {documentIndex: docIdx, pageNumber: num}; 
 
     } 
 
     num -= pdfDocs[docIdx].numPages; 
 
    } 
 
    
 
    return false; 
 
}; 
 

 
function getTotalPageCount() { 
 
    var totalPageCount = 0; 
 
    for (var docIdx = 0; docIdx < pdfDocs.length; docIdx++) { 
 
     totalPageCount += pdfDocs[docIdx].numPages; 
 
    } 
 
    return totalPageCount; 
 
} 
 

 
var loadedCount = 0; 
 
function load() { 
 
    // Load PDFs one after another 
 
    PDFJS.getDocument(urls[loadedCount]).then(function (pdfDoc_) { 
 
     console.log('loaded PDF ' + loadedCount); 
 
     pdfDocs.push(pdfDoc_); 
 
     loadedCount++; 
 
     if (loadedCount !== urls.length) { 
 
      return load(); 
 
     } 
 
     
 
     console.log('Finished loading'); 
 
     totalPageCount = getTotalPageCount(); 
 
     document.getElementById('page_count').textContent = totalPageCount; 
 

 
     // Initial/first page rendering 
 
     renderPage(pageNum); 
 
    });   
 
}

<!DOCTYPE html> 
 
<html> 
 
    <head> 
 
     <base href="https://mozilla.github.io/pdf.js/" /> 
 
     <meta charset="UTF-8"> 
 
     <title>Previous/Next example</title> 
 
    </head> 
 
    <body onload="load()"> 
 

 
     <div> 
 
      <button id="prev">Previous</button> 
 
      <button id="next">Next</button> 
 
      &nbsp; &nbsp; 
 
      <span>Page: <span id="page_num"></span>/<span id="page_count"></span></span> 
 
     </div> 
 

 
     <div> 
 
      <canvas id="the-canvas" style="border:1px solid black"></canvas> 
 
     </div> 
 

 
     <!-- for legacy browsers add compatibility.js --> 
 
     <script src="web/compatibility.js"></script> 
 

 
     <script src="build/pdf.js"></script> 
 

 
    </body> 
 
</html>

有关发送正确的CORS标头的服务器没有在那里可靠的测试文档的缘故，这个例子只是合并的默认文档的两个副本。如果您在自己的服务器上执行此操作，您当然可以将其添加到urls阵列中，以添加在同一个域中托管的任何文档。

Answer 2

你最好先合并服务器上的页面。