Question

我试图在浏览器中显示PDF，我发现了图书馆PDF.js，它是最受欢迎和建议最多的图书馆。文档虽然很清晰，但是我尝试使用最新的官方发行版2.0.943的文档并未呈现，但已加载（因为我看到的是正确的页数），但是看不到。

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<body>

    <!--<script src="//mozilla.github.io/pdf.js/build/pdf.js"></script>-->
    <script src="https://cdn.jsdelivr.net/npm/pdfjs-dist@2.0.943/build/pdf.js"></script>

    <h1>PDF.js Previous/Next example</h1>

    <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>

    <canvas id="the-canvas"></canvas>
    <script>
        $(document).ready(function () {

            var pdfData = atob(
                'JVBERi0xLjcKCjEgMCBvYmogICUgZW50cnkgcG9pbnQKPDwKICAvVHlwZSAvQ2F0YWxvZwog' +
                'IC9QYWdlcyAyIDAgUgo+PgplbmRvYmoKCjIgMCBvYmoKPDwKICAvVHlwZSAvUGFnZXMKICAv' +
                'TWVkaWFCb3ggWyAwIDAgMjAwIDIwMCBdCiAgL0NvdW50IDEKICAvS2lkcyBbIDMgMCBSIF0K' +
                'Pj4KZW5kb2JqCgozIDAgb2JqCjw8CiAgL1R5cGUgL1BhZ2UKICAvUGFyZW50IDIgMCBSCiAg' +
                'L1Jlc291cmNlcyA8PAogICAgL0ZvbnQgPDwKICAgICAgL0YxIDQgMCBSIAogICAgPj4KICA+' +
                'PgogIC9Db250ZW50cyA1IDAgUgo+PgplbmRvYmoKCjQgMCBvYmoKPDwKICAvVHlwZSAvRm9u' +
                'dAogIC9TdWJ0eXBlIC9UeXBlMQogIC9CYXNlRm9udCAvVGltZXMtUm9tYW4KPj4KZW5kb2Jq' +
                'Cgo1IDAgb2JqICAlIHBhZ2UgY29udGVudAo8PAogIC9MZW5ndGggNDQKPj4Kc3RyZWFtCkJU' +
                'CjcwIDUwIFRECi9GMSAxMiBUZgooSGVsbG8sIHdvcmxkISkgVGoKRVQKZW5kc3RyZWFtCmVu' +
                'ZG9iagoKeHJlZgowIDYKMDAwMDAwMDAwMCA2NTUzNSBmIAowMDAwMDAwMDEwIDAwMDAwIG4g' +
                'CjAwMDAwMDAwNzkgMDAwMDAgbiAKMDAwMDAwMDE3MyAwMDAwMCBuIAowMDAwMDAwMzAxIDAw' +
                'MDAwIG4gCjAwMDAwMDAzODAgMDAwMDAgbiAKdHJhaWxlcgo8PAogIC9TaXplIDYKICAvUm9v' +
                'dCAxIDAgUgo+PgpzdGFydHhyZWYKNDkyCiUlRU9G');

            // Loaded via <script> tag, create shortcut to access PDF.js exports.
            var pdfjsLib = window['pdfjs-dist/build/pdf'];

            // The workerSrc property shall be specified.
            pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdn.jsdelivr.net/npm/pdfjs-dist@2.0.943/build/pdf.worker.js';
            //pdfjsLib.GlobalWorkerOptions.workerSrc = '//mozilla.github.io/pdf.js/build/pdf.worker.js';

            // Using DocumentInitParameters object to load binary data.
            var loadingTask = pdfjsLib.getDocument({ data: pdfData });
            loadingTask.promise.then(function (pdf) {
                console.log('PDF loaded');

                // Fetch the first page
                var pageNumber = 1;
                pdf.getPage(pageNumber).then(function (page) {
                    console.log('Page loaded');

                    var scale = 1.5;
                    var viewport = page.getViewport({ scale: scale });

                    // Prepare canvas using PDF page dimensions
                    var canvas = document.getElementById('the-canvas');
                    var context = canvas.getContext('2d');
                    canvas.height = viewport.height;
                    canvas.width = viewport.width;

                    // Render PDF page into canvas context
                    var renderContext = {
                        canvasContext: context,
                        viewport: viewport
                    };
                    var renderTask = page.render(renderContext);
                    renderTask.promise.then(function () {
                        console.log('Page rendered');
                    });
                });
            }, function (reason) {
                // PDF loading error
                console.error(reason);
            });
        });
    </script>
</body>
</html>

官方示例提琴：https://jsfiddle.net/pdfjs/wagvs9Lf/?utm_source=website&utm_medium=embed&utm_campaign=wagvs9Lf

我的小提琴（仅版本）：https://jsfiddle.net/94x2ozbq/

根据我的发现：var viewport = page.getViewport({ scale: scale })返回高度和宽度等于NaN的对象

Answer 1

您需要对renderPage()中的以下行进行一些修改，在当前版本中该行需要一个对象，但是在2.0.943中需要一个数字：

发件人：

var viewport = page.getViewport({scale: scale});

收件人：

var viewport = page.getViewport(scale);

PDF.js 2.0.943无法在浏览器中呈现PDF

1 个答案: