import html2canvas from "html2canvas";
import jsPDF from "jspdf";
import JSZip from "jszip";
import FileSaver from "file-saver";
function downPdf () {
let zipData = []
const element = document.getElementById("demo")
const w = element.offsetWidth
const h = element.offsetHeight
const offsetTop = element.offsetTop
const offsetLeft = element.offsetLeft
const canvas = document.createElement("canvas")
let abs = 0
const win_i = document.body.clientWidth
const win_o = window.innerWidth
if (win_o > win_i) {
abs = (win_o - win_i) / 2
}
canvas.width = w * 2
canvas.height = h * 2
const context = canvas.getContext("2d")
context.scale(2, 2)
context.translate(-offsetLeft - abs, -offsetTop)
// 这里默认横向没有滚动条的情况,因为offset.left(),有无滚动条的时候存在差值,因此translate的时候,要把这个差值去掉
html2canvas(element, {
allowTaint: true,
scale: 2, // 提升画面质量,但是会增加文件大小
}).then((canvas) => {
const contentWidth = canvas.width
const contentHeight = canvas.height
// 一页pdf显示html页面生成的canvas高度
const pageHeight = (contentWidth / 592.28) * 841.89
// 未生成pdf的html页面高度
const leftHeight = contentHeight
// 页面偏移
const position = 0
// a4纸的尺寸[595.28,841.89],html页面生成的canvas在pdf中图片的宽高
const imgWidth = 595.28
const imgHeight = (592.28 / contentWidth) * contentHeight
const pageDate = canvas.toDataURL("image/jpeg", 1.0)
const pdf = new jsPDF("", "pt", "a4")
// 有两个高度需要区分,一个是html页面的实际高度,和生成pdf的页面的高度(841.89)
// 当内容未超过pdf一页显示的范围,无需分页
if (leftHeight < pageHeight) {
pdf.addImage(pageDate, "JPEG", 0, position, imgWidth, imgHeight)
} else {
// 分页
while (leftHeight > 0) {
pdf.addImage(pageDate, "JPEG", 0, position, imgWidth, imgHeight)
leftHeight -= pageHeight
position -= 841.89
// 避免添加空白页
if (leftHeight > 0) {
pdf.addPage()
}
}
}
zipData.push({
PDF: pdf,
name: `${code}.pdf`,
})
const zip = new JSZip()
if (zipData.length === downList.length) {
for (let i = 0
const { PDF, name } = zipData[i]
zip.file(`${name}.pdf`, PDF.output("blob"))
}
zip.generateAsync({ type: "blob" }).then((content) => {
FileSaver.saveAs(content, `订单`)
})
}
// pdf.save(`${code}.pdf`)
})
}
<div
id="demo"
className="smModal"
style={{ width: "800px", margin: "0 auto" }}
>
<DownLoad downList={downList} isSuccessFun={isSuccessFun} />
</div>