基于html2canva jspdf 实现前端页面加水印 并导出页面PDF; 下载完整代码请访问uni-app插件市场地址：https://ext.dcloud.net.cn/plugin?id=12761
效果图如下:
代码实现如下:
# 使用方法
```使用方法
<!-- 引入加入 导出pdf插件 -->
<script type="text/javascript" src="./static/html2canvas.js"></script>
<script type="text/javascript" src="./static/jspdf.debug.js"></script>
// 调用页面加水印方法
this.watermark({
"watermark_txt": "中国广东cc.gd"
});
// 调用下载pdf报告方法
downKcReport();
```
#### HTML代码部分
```html
<template>
<view class="content">
<view class="exportPdfBtn" @click="downKcReport()">导出PDF</view>
<!-- 可视化 -->
<view style="background-color: white; border-radius: 4px; margin-top: -4px;">
<!-- 柱形图 堆叠 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px;"> 柱形图 堆叠
</h4>
<div class="mui-content-padded">
<div id="dsj_zscq" style="width: calc(100vw - 40px); height: 280px;"></div>
</div>
<!-- 折线图 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px;"> 折线图
</h4>
<div class="mui-content-padded">
<div id="dsj_cxcg" style="width: calc(100vw - 40px); margin: -18px 0px; height: 280px;">
</div>
</div>
<!-- 柱状图 + 折线图-->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
柱状图 + 折线图 </h4>
<div class="mui-content-padded">
<div id="dsj_zlhjl" style="width: calc(100vw - 40px); height: 290px;"></div>
</div>
<!-- 有效知识产权结构 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
饼图 </h4>
<div class="mui-content-padded">
<div id="dsj_zscqjg" style="width: calc(100vw - 40px); height: 306px;"></div>
</div>
<!-- 专利iPC结构 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
树形结构图 </h4>
<div class="mui-content-padded">
<div id="dsj_zlipc_content"
style="margin-left: -10px; width: calc(100vw - 40px); height: auto; margin-bottom: 30px;">
</div>
</div>
<!-- 柱状图 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
柱状图 </h4>
<div class="mui-content-padded">
<div id="dsj_zljz" style="width: calc(100vw - 40px); height: 280px;"></div>
</div>
<!-- 专利法律状态分布 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
饼图 </h4>
<div class="mui-content-padded">
<div id="dsj_zlfl" style="width: calc(100vw - 40px); height: 280px;"></div>
</div>
<!-- 专利寿命分布 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
柱状图 </h4>
<div class="mui-content-padded">
<div id="dsj_zlsm" style="width: calc(100vw - 40px); height: 280px;"></div>
</div>
<!-- 树形结构图 -->
<h4 style="margin-left: 12px; font-size: 16px; height: 30px; line-height: 30px; margin-top: 0px;">
树形结构图 </h4>
<div class="mui-content-padded">
<div id="dsj_zllhsq" style="width: calc(100vw - 40px); height: auto; margin-bottom: 30px;">
</div>
</div>
</view>
</view>
</template>
```
#### JS代码 （引入组件 填充数据）
```javascript
<script>
import myIndex from '../index/index.js'
export default {
data() {
return {
title: 'Hello'
}
},
mounted() {
// 刷新Echart数据
this.refreshEchartData();
},
onLoad() {
// 页面加水印方法
this.watermark({
"watermark_txt": "中国广东cc.gd"
});
},
methods: {
// 页面加水印方法
watermark(settings) {
//默认设置
var defaultSettings = {
watermark_txt: "text",
watermark_x: 20, //水印起始位置x轴坐标
watermark_y: 80, //水印起始位置Y轴坐标
watermark_rows: 80, //水印行数
watermark_cols: 20, //水印列数
watermark_x_space: 80, //水印x轴间隔
watermark_y_space: 102, //水印y轴间隔
watermark_color: '#aaa', //水印字体颜色
watermark_alpha: 0.4, //水印透明度
watermark_fontsize: '14px', //水印字体大小
watermark_font: '微软雅黑', //水印字体
watermark_width: 180, //水印宽度
watermark_height: 80, //水印长度
watermark_angle: 20 //水印倾斜度数
};
//采用配置项替换默认值，作用类似jquery.extend
if (arguments.length === 1 && typeof arguments[0] === "object") {
console.log("arguments = " + JSON.stringify(arguments[0]));
// 获取参数配置
var src = arguments[0];
for (let key in src) {
if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key])
continue;
else if (src[key])
defaultSettings[key] = src[key];
}
}
var oTemp = document.createDocumentFragment();
//获取页面最大宽度
var page_width = Math.max(document.body.scrollWidth, document.body.clientWidth);
var cutWidth = page_width * 0.0150;
var page_width = page_width - cutWidth;
//获取页面最大高度
var page_height = Math.max(document.body.scrollHeight, document.body.clientHeight) + 2860;
// var page_height = document.body.scrollHeight+document.body.scrollTop;
//如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
if (defaultSettings.watermark_cols == 0 || (parseInt(defaultSettings.watermark_x + defaultSettings
.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (
defaultSettings.watermark_cols - 1)) > page_width)) {
defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + defaultSettings
.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings
.watermark_x_space));
defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x -
defaultSettings
.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));
}
//如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
if (defaultSettings.watermark_rows == 0 || (parseInt(defaultSettings.watermark_y + defaultSettings
.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (
defaultSettings.watermark_rows - 1)) > page_height)) {
defaultSettings.watermark_rows = parseInt((defaultSettings.watermark_y_space + page_height -
defaultSettings
.watermark_y) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));
defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y) -
defaultSettings
.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));
}
var x;
var y;
for (var i = 0; i < defaultSettings.watermark_rows; i++) {
y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings
.watermark_height) * i;
for (var j = 0; j < defaultSettings.watermark_cols; j++) {
x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings
.watermark_x_space) *
j;
var mask_div = document.createElement('div');
mask_div.id = 'mask_div' + i + j;
mask_div.className = 'mask_div';
mask_div.appendChild(document.createTextNode(defaultSettings.watermark_txt));
//设置水印div倾斜显示
mask_div.style.webkitTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
mask_div.style.MozTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
mask_div.style.msTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
mask_div.style.OTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
mask_div.style.transform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
mask_div.style.visibility = "";
mask_div.style.position = "absolute";
mask_div.style.left = x + 'px';
mask_div.style.top = y + 'px';
mask_div.style.overflow = "hidden";
mask_div.style.zIndex = "9999";
mask_div.style.pointerEvents = 'none'; //pointer-events:none 让水印不遮挡页面的点击事件
//mask_div.style.border="solid #eee 1px";
mask_div.style.opacity = defaultSettings.watermark_alpha;
mask_div.style.fontSize = defaultSettings.watermark_fontsize;
mask_div.style.fontFamily = defaultSettings.watermark_font;
mask_div.style.color = defaultSettings.watermark_color;
mask_div.style.textAlign = "center";
mask_div.style.width = defaultSettings.watermark_width + 'px';
mask_div.style.height = defaultSettings.watermark_height + 'px';
mask_div.style.display = "block";
oTemp.appendChild(mask_div);
};
};
document.body.appendChild(oTemp);
},
// 下载pdf报告
downKcReport() {
html2canvas(
document.body, {
scale: 2,
dpi: 192, //导出pdf清晰度
onrendered: function(canvas) {
var contentWidth = canvas.width;
var contentHeight = canvas.height;
//一页pdf显示html页面生成的canvas高度;
var pageHeight = contentWidth / 592.28 * 841.89;
//未生成pdf的html页面高度
var leftHeight = contentHeight;
//pdf页面偏移
var position = 0;
//html页面生成的canvas在pdf中图片的宽高（a4纸的尺寸[595.28,841.89]）
var imgWidth = 595.28;
var imgHeight = 592.28 / contentWidth * contentHeight;
var pageData = canvas.toDataURL('image/jpeg', 1.0);
var 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(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
} else {
while (leftHeight > 0) {
pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
leftHeight -= pageHeight;
position -= 841.89;
//避免添加空白页
if (leftHeight > 0) {
pdf.addPage();
}
}
}
pdf.save(name + '.pdf');
console.log('成功导出pdf');
},
//背景设为白色（默认为黑色）
background: "#fff"
})
},
refreshEchartData() {
// 返回数据需在json转换格式工具 转成Json格式
let result = {
"data": {
"unionCompanyNum": 4,
"goldList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"fmsqYx": "1",
"cfmwyxzscqsl": "1",
"years": "1",
"yxzscqsl": "1",
"dnzlhjl": "1"
}],
"patentLifeList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"percentage": "1",
"quantity": "1",
"scope": "1-3",
"totalNum": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"percentage": "1",
"quantity": "1",
"scope": "3-5",
"totalNum": "2"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"percentage": "1",
"quantity": "3",
"scope": "5-10",
"totalNum": "3"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"percentage": "1",
"quantity": "3",
"scope": "10-",
"totalNum": "4"
}],
"patentValueList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"fmgbZs": "1",
"fmsqYx": "1",
"syxxYx": "1",
"wgsjYx": "1",
"scope": "0-5",
"totalNum": "1",
"percentageHighRights": "1",
"percentageHigh": "1",
"dspw": "1",
"jslypw": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"fmgbZs": "1",
"fmsqYx": "1",
"syxxYx": "1",
"wgsjYx": "1",
"scope": "5-10",
"totalNum": "1",
"percentageHighRights": "1",
"percentageHigh": "1",
"dspw": "1",
"jslypw": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"fmgbZs": "1",
"fmsqYx": "2",
"syxxYx": "3",
"wgsjYx": "4",
"scope": "90-100",
"totalNum": "10"
}],
"legalList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"underTrial": "1",
"invalid": "1",
"efficient": "1",
"totalNum": "1",
"percentage": "1"
}],
"propertyRightList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"fmgbZs": "1",
"fmgbZsP": "1",
"fmsqYx": "1",
"fmsqYxP": "1",
"syxxYx": "1",
"syxxYxP": "1",
"wgsjYx": "1",
"wgsjYxP": "1",
"rzYx": "1",
"rzYxP": "1",
"maxPercentage": "1",
"maxPercentageRights": "1",
"dspw": "1",
"jslypw": "1"
}],
"unionPatentNum": 13,
"ipcList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"ipcDept": "1",
"ipcClass": "1",
"ipcNum": "1",
"ipcZbClass": "1",
"ipcZb": "1",
"dspw": "1",
"jslypw": "1"
}],
"yearList": [{
"isNewRecord": true,
"comId": "1",
"fmgbZs": "1",
"fmsqYx": "1",
"syxxYx": "1",
"wgsjYx": "1",
"rzYx": "1",
"years": "2022",
"dnkjcxcgkbjshl": "1",
"socialCode": "123456"
}, {
"isNewRecord": true,
"comId": "1",
"years": "2023",
"dnkjcxcgkbjshl": "2",
"socialCode": "123456"
}, {
"isNewRecord": true,
"comId": "1",
"years": "2026",
"dnkjcxcgkbjshl": "6",
"socialCode": "123456"
}, {
"isNewRecord": true,
"comId": "1",
"years": "2027",
"dnkjcxcgkbjshl": "7",
"socialCode": "123456"
}],
"unionList": [{
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"unionName": "测试5",
"unionNum": "5",
"unionCompany": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"unionName": "测试4",
"unionNum": "4",
"unionCompany": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"unionName": "测试3",
"unionNum": "3",
"unionCompany": "1"
}, {
"isNewRecord": true,
"comId": "1",
"socialCode": "123456",
"unionName": "测试1",
"unionNum": "1",
"unionCompany": "1"
}]
},
"statusCode": 200,
"header": {
"date": "Tue, 30 May 2023 07:08:28 GMT",
"powered-by": "JeeSite V5.0.1 0",
"transfer-encoding": "chunked",
"content-type": "application/json"
},
"errMsg": "request:ok"
};
let resultData = result.data;
if (resultData.yearList != undefined && resultData.yearList.length > 0) {
console.log('执行图表1');
// 填充图表1 2
myIndex.fillChartOneTwo(resultData.yearList);
}
if (resultData.goldList != undefined && resultData.goldList.length > 0) {
// 填充图表3
myIndex.fillChartThree(resultData.goldList);
}
if (resultData.propertyRightList != undefined && resultData.propertyRightList.length > 0) {
// 填充图表4
myIndex.fillChartFour(resultData.propertyRightList);
}
if (resultData.ipcList != undefined && resultData.ipcList.length > 0) {
// 填充图表5
myIndex.fillChartFive(resultData.ipcList);
}
if (resultData.patentValueList != undefined && resultData.patentValueList.length > 0) {
// 填充图表6
myIndex.fillChartSix(resultData.patentValueList);
}
if (resultData.legalList != undefined && resultData.legalList.length > 0) {
// 填充图表7 法律
myIndex.fillChartSeven(resultData.legalList);
}
if (resultData.patentLifeList != undefined && resultData.patentLifeList.length > 0) {
// 填充图表8 寿命
myIndex.fillChartEight(resultData.patentLifeList);
}
if (resultData.unionList != undefined && resultData.unionList.length > 0) {
// 填充图表9 专利联合
myIndex.fillChartNine(resultData, "广汽集团");
}
}
}
}
</script>
```
#### CSS
```CSS
<style>
.content {
display: flex;
flex-direction: column;
align-items: center;
justify-content: center;
}
.mui-content-padded {
margin: 10px 8px;
}
.mui-content-padded div {
font-size: 13px;
}
.exportPdfBtn {
width: 100px;
height: 40px;
line-height: 40px;
margin-top: 20px;
background-color: greenyellow;
text-align: center;
}
</style>
```
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