[我有一个脚本，该脚本使用HTML2Canvas捕获页面内div的屏幕截图，然后使用jsPDF将其转换为pdf。
问题是生成的pdf仅一页，在某些情况下，屏幕截图需要一页以上。例如，屏幕截图大于8.5x11。宽度很好，但是我需要它来创建多个页面以适合整个屏幕截图。
这是我的剧本：
var pdf = new jsPDF('portrait', 'pt', 'letter');
$('.export').click(function() {
pdf.addHTML($('.profile-expand')[0], function () {
pdf.save('bfc-schedule.pdf');
});
});
关于如何修改它以允许多页的任何想法？
pdf.addHtml如果网页上有SVG图片，则无法使用。我在这里复制解决方案，基于图片已经在画布中。
以下是我发现可以使用的数字（纸张的宽度和高度）。它仍然在页面之间创建一些重叠的部分，但是对我来说足够好。如果您可以从jsPDF中找到正式编号，请使用它们。
var imgData = canvas.toDataURL('image/png');
var imgWidth = 210;
var pageHeight = 295;
var imgHeight = canvas.height * imgWidth / canvas.width;
var heightLeft = imgHeight;
var doc = new jsPDF('p', 'mm');
var position = 0;
doc.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight);
heightLeft -= pageHeight;
while (heightLeft >= 0) {
position = heightLeft - imgHeight;
doc.addPage();
doc.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight);
heightLeft -= pageHeight;
}
doc.save( 'file.pdf');`
您可以使用addhtml的分页选项，如下所示：
var options = {
background: '#fff',
pagesplit: true
};
var doc = new jsPDF(orientation, 'mm', pagelayout);
doc.addHTML(source, 0, 0, options, function () {
doc.save(filename + ".pdf");
HideLoader();`enter code here`
});
注意：这将破坏多页上的html，但是这些页面会被拉伸。到目前为止，在addhtml中拉伸是一个问题，我仍然无法在Internet上找到如何解决此问题的方法。
我能够使用async功能来完成它。
(async function loop() {
var pages = [...]
for (var i = 0; i < pages.length; i++) {
await new Promise(function(resolve) {
html2canvas(pages[i], {scale: 1}).then(function(canvas) {
var img=canvas.toDataURL("image/png");
doc.addImage(img,'JPEG', 10, 10);
if ((i+1) == pages.length) {
doc.save('menu.pdf');
} else {
doc.addPage();
}
resolve();
});
});
}
})();
这是我的方法，也使用jspdf和html2canvas对我做得很好：
我正在使用一个包装器节点，其中包含要转换为pdf的内容：
<div id="main-content">
<!-- the content goes here -->
</div>
<!-- and a button somewhere in the dom -->
<a href="javascript:genPDF()">
<i class="far fa-file-pdf"></i> Download PDF
</a>
这是JS集成（我只检查了此版本），然后调用：
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.3.3/jspdf.min.js"></script>
<script src="https://html2canvas.hertzen.com/dist/html2canvas.js"></script>
<script type="text/javascript">
const documentSlug = "some Slug";
const documentTitle ="Some Title";
function genPDF(){
let html2pdf = new pdfView();
html2pdf.generate();
}
</script>
这里您可以看到pdf版本。我将生成部分封装在一个额外的js对象中（您还需要包含此文件）：
//assuming jquery is in use
let pdfView = function(){
//assuming documentSlug is a constant set earlier
this.documentSlug = documentSlug;
//assuming documentTitle is a constant set earlier
this.documentTitle = documentTitle;
//in this html node the part which shall be converted to pdf
this.nodeId = "main-content";
};
pdfView.prototype.generate = function(){
let self = this;
this.prepareDocumentToPrint();
//variables
let HTML_Width = $("#"+self.nodeId).width();
let HTML_Height = $("#"+self.nodeId).height();
let top_left_margin = 15;
let PDF_Width = HTML_Width+(top_left_margin*2);
let PDF_Height = (PDF_Width*1.5)+(top_left_margin*2);
this.pdfWidth = PDF_Width;
this.pdfHeight = PDF_Height;
let canvas_image_width = HTML_Width;
let canvas_image_height = HTML_Height;
let totalPDFPages = Math.ceil(HTML_Height/PDF_Height)-1;
html2canvas($("#"+self.nodeId)[0],{allowTaint:true, scale: 2}).then(function(canvas) {
canvas.getContext('2d');
//console.log(canvas.height+" "+canvas.width);
let imgData = canvas.toDataURL("image/jpeg", 1.0);
let pdf = new jsPDF('p', 'mm', [PDF_Width, PDF_Height]);
pdf.addImage(imgData, 'JPG', top_left_margin, top_left_margin,canvas_image_width,canvas_image_height);
pdf = self.addPdfHeader(pdf);
pdf = self.addPdfFooter(pdf, 1);
for (let i = 1; i <= totalPDFPages; i++) {
pdf.addPage(PDF_Width, PDF_Height);
pdf.addImage(imgData, 'JPG', top_left_margin, -(PDF_Height*i)+(top_left_margin*4) + top_left_margin,canvas_image_width,canvas_image_height);
pdf = self.addPdfHeader(pdf);
pdf = self.addPdfFooter(pdf, (i+1));
}
pdf.save(self.documentSlug+".pdf");
self.resetDocumentAfterPrint();
});
};
//this one sets a fixed viewport, to be able to
//get the same pdf also on a mobile device. I also
//have a css file, which holds the rules for the
//document if the body has the .printview class added
pdfView.prototype.prepareDocumentToPrint = function(){
let viewport = document.querySelector("meta[name=viewport]");
viewport.setAttribute('content', 'width=1280, initial-scale=0.1');
$('body').addClass("printview");
window.scrollTo(0,0);
};
pdfView.prototype.addPdfHeader = function(pdf){
pdf.setFillColor(255,255,255);
pdf.rect(0, 0, this.pdfWidth, 40, "F");
pdf.setFontSize(40);
pdf.text("Document: "+this.documentTitle+" - Example Lmtd. Inc. (Whatsoever)", 50, 22);
return pdf;
};
pdfView.prototype.addPdfFooter = function(pdf, pageNumber){
pdf.setFillColor(255,255,255);
pdf.rect(0, pdf.internal.pageSize.height - 40, this.pdfWidth, this.pdfHeight, "F");
pdf.setFontSize(40);
pdf.text("Seite "+pageNumber, 50, pdf.internal.pageSize.height - 20);
return pdf;
};
//and this one resets the doc back to normal
pdfView.prototype.resetDocumentAfterPrint = function(){
$('body').removeClass("printview");
let viewport = document.querySelector("meta[name=viewport]");
viewport.setAttribute('content', 'device-width, initial-scale=1, shrink-to-fit=no');
};
.printview案例的我的CSS示例：
body.printview #header,
body.printview footer
{
display: none !important;
}
body.printview{
margin-top: 0px !important;
}
body.printview #main-content{
margin-top: 0px !important;
}
body.printview h1{
margin-top: 40px !important;
}
享受
您提供的链接对@Code Spy的贡献，这是此漏洞的基础。
您可以尝试：
$('#cmd2').click(function () {
var len = 4; //$x(".//body/div/div").length
var pdf = new jsPDF('p', 'mm','a4');
var position = 0;
Hide
for (let i = 1;i <= len; i++){
html2canvas(document.querySelector('#pg'+i),
{dpi: 300, // Set to 300 DPI
scale: 1 // Adjusts your resolution
}).then(canvas => {
pdf.addImage(canvas.toDataURL("images/png", 1), 'PNG', 0,position, 210, 295);
if (i == len){
pdf.save('sample-file.pdf');
}else{
pdf.addPage();
}
});
}
});