通過純js將網頁保存為pdf,A4分頁,無需服務端參與
1.引入js庫文件:
<script src="../static/jspdf/html2canvas.js"></script><script src="../static/jspdf/jsPdf.debug.js"></script>
2.思路:
用html2canvas截取頁面(html2canvas就是這樣一款前端插件,它的原理是將Dom節點在Canvas里邊畫出來),然后用jsPDF來生成pdf文件。
3.核心代碼:
為了保證生成的pdf空白區域沒有黑色背景,在操作之前先把背景設置為白色(因為沒有背景色,截取時會以黑色填充)
$("#"+divID).css("background-color","white");
解決html2canvas截取頁面太模糊,創建一個新的canvas:
var canvas_new = document.createElement("canvas");var scale = 2;var w = parseInt(window.getComputedStyle(document.querySelector("#"+divID)).width);var h = parseInt(window.getComputedStyle(document.querySelector("#"+divID)).height);
將canvas畫布放大若干倍,然后盛放在較小的容器內,就顯得不模糊了:
canvas_new.width = w * scale;canvas_new.height = h * scale;canvas_new.getContext("2d").scale(scale, scale);
進行導出:
var options = {canvas: canvas_new};html2canvas(document.querySelector("#"+divID),options)..then(function(canvas) {var contentWidth = canvas.width;var contentHeight = canvas.height;//一頁pdf顯示html頁面生成的canvas高度;var pageHeight = contentWidth / 592.28 * 841.89;//未生成pdf的html頁面高度var leftHeight = contentHeight;//頁面偏移var position = 0;//a4紙的尺寸[595.28,841.89],html頁面生成的canvas在pdf中圖片的寬高var imgWidth = 595.28;var imgHeight = 592.28/contentWidth * contentHeight+45;var pageData = canvas.toDataURL('image/jpeg', 1.0);var pdf = new jsPDF('', 'pt', 'a4');//有兩個高度需要區分,一個是html頁面的實際高度,和生成pdf的頁面高度(841.89)//當內容未超過pdf一頁顯示的范圍,無需分頁if (leftHeight < pageHeight) {pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight );} else {while(leftHeight > 0) {pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)leftHeight -= pageHeight;position -= 841.89;//避免添加空白頁if(leftHeight > 0) {pdf.addPage();}}}pdf.save('name.pdf');
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作者:致虛極POLE守靜篤
來源:CSDN
原文:https://blog.csdn.net/u011821334/article/details/79389426
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內容解析By:CSDN,CNBLOG博客文章一鍵轉載插件