PDF转图片 + 分页-Toy模板网

这篇具有很好参考价值的文章主要介绍了PDF转图片 + 分页。希望对大家有所帮助。如果存在错误或未考虑完全的地方，请大家不吝赐教，您也可以点击"举报违法"按钮提交疑问。

PDF转图片有两种方式，一种是请求所有分页后合成一张图片，一种是分页加载
本文推荐后者，前者在实操中 pdf页码过大时转换超时导致失败

本文需要的依赖是pdf.js pdf.worker.js jquery.js 当然在git上都可以找到

也可以使用本文上传的资源依赖，在这篇文章的上方下载。文章来源地址https://www.toymoban.com/news/detail-588987.html

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1,user-scalable=no" />
    <title>PDF文件转图片</title>
    <script src="/assets/js/jquery.js"></script>
    <script src="/assets/v2/js/pdf.js"></script>
    <script src="/assets/v2/js/pdf.worker.js"></script>
</head>

<body>
    <div class="all_cont" style=" display: flex;flex-direction: column;align-items: center;">
        <div class="container_cont" style="margin-top:1%;position: relative;display: flex;align-items: center;justify-content: center;">
            <button id="prevpage" style=" width: 120px;height: 30px;background: none;border: 1px solid #b1afaf;border-radius: 5px;font-size: 12px;font-weight: 1000;color: #384240;cursor: pointer;outline: none;margin: 0 0.5%">上一页</button>
            <button id="nextpage" style=" width: 120px;height: 30px;background: none;border: 1px solid #b1afaf;border-radius: 5px;font-size: 12px;font-weight: 1000;color: #384240;cursor: pointer;outline: none; margin: 0 0.5%">下一页</button>
            <input style="display:none" id="chooseFile" type="file" accept="application/pdf">
        </div>
        <div class="container_cont">
            <div id="container" style=" margin-top: 1%;border-radius: 2px;border: 2px solid #a29b9b;"></div>
            <img id="imgloading" style="position: absolute;top: 50%;left: 50%;transform: translate(-50%, -50%); display:none" src="/assets/images/loading.gif">
        </div>
    </div>
</body>
<script>
    var currentPages, totalPages //声明一个当前页码及总页数变量
    var url = '/media/files/db01a18eaeb9f87ca49b22bcb61f2dc17ecd72d4.pdf';
    var my_pdf = '';

    function init() {
        loadPdfFromUrl(url);
    }

    function loadPdfFromUrl() {
        $('#imgloading').css('display', 'block');
        $('#container').empty(); //清空上一PDF文件展示图
        currentPages = 1; //重置当前页数
        totalPages = 0; //重置总页数
        pdfjsLib.getDocument(url).promise.then(function(pdf) { //调用pdf.js获取文件
            console.log('gl----pdf', pdf);
            my_pdf = pdf
            if (pdf) {
                totalPages = pdf.numPages; //获取pdf文件总页数
                $('#currentPages').text('1/');
                $('#totalPages').text(totalPages);
                //遍历动态创建canvas
                for (var i = 1; i <= totalPages; i++) {
                    var canvas = document.createElement('canvas');
                    canvas.id = 'pageNum' + i;
                    $('#container').append(canvas);
                    var context = canvas.getContext('2d');
                    renderImg(pdf, i, context);
                }
            }
        });
    }

    function renderImg(pdfFile, pageNumber, canvasContext) {
        console.log('gl---pdfFile', pdfFile);
        pdfFile.getPage(pageNumber).then(function(page) { //逐页解析PDF
            var viewport = page.getViewport({
                scale: 1
            }); // 页面缩放比例
            var newcanvas = canvasContext.canvas;
            //设置canvas真实宽高
            newcanvas.width = viewport.width;
            newcanvas.height = viewport.height;
            //设置canvas在浏览中宽高
            newcanvas.style.width = '100%';
            newcanvas.style.height = '100%';
            //默认显示第一页，其他页隐藏
            if (pageNumber != 1) {
                newcanvas.style.display = 'none';
            }
            var renderContext = {
                canvasContext: canvasContext,
                viewport: viewport
            };
            page.render(renderContext); //渲染生成
        });
        $('#imgloading').css('display', 'none');
        return;
    };
    $('#prevpage').click(function() {
        if (!currentPages || currentPages <= 1) {
            return;
        }
        nowpage = currentPages;
        currentPages--;
        $('#currentPages').text(currentPages + '/');
        var prevcanvas = document.getElementById('pageNum' + currentPages);
        var currentcanvas = document.getElementById('pageNum' + nowpage);
        currentcanvas.style.display = 'none';
        prevcanvas.style.display = 'block';
    })
    $('#nextpage').click(function() {
        if (!currentPages || currentPages >= totalPages) {
            return;
        }
        nowpage = currentPages;
        currentPages++;
        $('#currentPages').text(currentPages + '/');
        var nextcanvas = document.getElementById('pageNum' + currentPages);
        var currentcanvas = document.getElementById('pageNum' + nowpage);
        currentcanvas.style.display = 'none';
        nextcanvas.style.display = 'block';
    })
    init()
</script>

</html>