方法一
需要安装file-saver,html2canvas插件
handleExport() {
let htmlDom = document.querySelector('#centerPark');
var FileSaver = require('file-saver');
html2canvas(htmlDom, {
allowTaint: false, //允许污染
taintTest: true, //在渲染前测试图片(没整明白有啥用)
useCORS: true, //使用跨域(当allowTaint为true时这段代码没什么用,下面解释)
background: "#fff",
}).then(canvas => {
if (navigator.msSaveBlob) {
navigator.msSaveBlob(canvas.msToBlob(), 'map.png');
} else {
canvas.toBlob(function (blob) {
FileSaver.saveAs(blob, 'map.png');
});
}
})
},
对于地图截图也可以
handleExport() {
let map = this.mymap;
var FileSaver = require('file-saver')
map.once('rendercomplete', function (event) {
var canvas = event.context.canvas;
if (navigator.msSaveBlob) {
navigator.msSaveBlob(canvas.msToBlob(), 'map.png');
} else {
canvas.toBlob(function (blob) {
FileSaver.saveAs(blob, 'map.png');
});
}
});
map.renderSync();
},
这个方法的问题是标记标绘可以截不上。
方法二
首先进行预览后在导出成pdf，如下图所示：
image.png
<el-dialog title="专题报告预览" :visible.sync="imgDialogVisible" width="50%" :before-close="handleClose" @open="openDialog">
<!-- <span>点击图片进行下载</span> -->
<el-form label-width="100px">
<div class="row">
<el-alert title="点击图片可单独保存图片" type="info">
</el-alert>
</div>
<div class="row" style="margin-top:10px">
<el-row>
<el-col :span="8">
<el-form-item label="制作单位：">
<el-input placeholder="请输入制作单位" v-model="unit"></el-input>
</el-input>
</el-form-item>
</el-col>
<el-col :span="8">
<el-form-item label="制作人：">
<el-input placeholder="请输入制作人名称" v-model="producer"></el-input>
</el-input>
</el-form-item>
</el-col>
<el-col :span="8">
<el-form-item label="签发人：">
<el-input v-model="issuer" placeholder="请输入签发人名称" value="admin"></el-input>
</el-form-item>
</el-col>
</el-row>
</div>
<div class="row">
<el-form-item label="报告内容：">
<el-input type="textarea" :rows="2" placeholder="请输入内容" v-model="textarea">
</el-input>
</el-form-item>
<!-- <span><label for="">内容：</label> </span> -->
</div>
</el-form>
<!-- 报告主体 -->
<div id="dialogPage">
<div class="dialog-title" align="center">专题报告</div>
<div class="row">
<span>
{{unit}}
</span>
<span style="" class="right">时间：{{nowDate | formatdatezhSimple}}</span>
</div>
<div class="row">
<span>制作人：{{this.producer}}</span>
<span class="right">签发人：{{this.issuer}}</span>
<div class="line1" style="border-bottom: 2px solid #ff6600;width: 100%; margin: 3px 0;"></div>
<div class="line2" style="border-bottom: 8px solid #ff6600;width: 100%;"></div>
</div>
<div class="row content">{{textarea}}</div>
<a href="" id="imgA" title="点击下载">
<div id="downloadImg"></div>
</a>
</div>
<div class="right">
<el-button type="primary" @click="download">导出pdf</el-button>
</div>
<div id="result" style="height: 300px;"></div>
</el-dialog>
js
download() {
var element = document.querySelector("#dialogPage") // 这个dom元素是要导出pdf的div容器
var w = element.style.width; // 获得该容器的宽
var h = element.style.height; // 获得该容器的高
var offsetTop = element.offsetHeight; // 获得该容器到文档顶部的距离
var offsetLeft = element.offsetWidth; // 获得该容器到文档最左的距离
var canvas = document.createElement("canvas");
var abs = 0;
// var win_i = $(window).width(); // 获得当前可视窗口的宽度（不包含滚动条）
var win_i = document.body.offsetWidth; // 获得当前可视窗口的宽度（不包含滚动条）
var win_o = window.innerWidth; // 获得当前窗口的宽度（包含滚动条）
if (win_o > win_i) {
abs = (win_o - win_i) / 2; // 获得滚动条长度的一半
}
canvas.width = w * 2; // 将画布宽&&高放大两倍
canvas.height = h * 2;
var context = canvas.getContext("2d");
context.scale(2, 2);
context.translate(-offsetLeft - abs, -offsetTop);
// 这里默认横向没有滚动条的情况，因为offset.left(),有无滚动条的时候存在差值，因此
// translate的时候，要把这个差值去掉
html2canvas(element).then(canvas => {
var contentWidth = canvas.width;
var contentHeight = canvas.height;
//一页pdf显示html页面生成的canvas高度;
var pageHeight = contentWidth / 592.28 * 841.89;
//未生成pdf的html页面高度
var leftHeight = contentHeight;
//页面偏移
var position = 0;
//a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
var imgWidth = 595.28;
var imgHeight = 592.28 / contentWidth * contentHeight;
var pageData = canvas.toDataURL('image/jpeg', 1.0);
var pdf = new jsPDF('', 'pt', 'a4');
//有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
//当内容未超过pdf一页显示的范围，无需分页
if (leftHeight < pageHeight) {
pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
} else { // 分页
while (leftHeight > 0) {
pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
leftHeight -= pageHeight;
position -= 841.89;
//避免添加空白页
if (leftHeight > 0) {
pdf.addPage();
}
}
}
let now = new Date();
// 调用全局过滤器
let date = this.$options.filters.formatdatezhSimple(now);
pdf.save(date + ' 专题报告.pdf');
})
},
handleExport1() {
this.imgDialogVisible = true;
},
openDialog() {
let htmlDom = document.querySelector('#centerPark')
html2canvas(htmlDom, {
allowTaint: false, //允许污染
taintTest: true, //在渲染前测试图片(没整明白有啥用)
useCORS: true, //使用跨域(当allowTaint为true时这段代码没什么用,下面解释)
background: "#fff",
}).then(canvas => {
// this.imgDialogVisible = true;
let img = document.querySelector('#downloadImg');
if (img.hasChildNodes()) {
var childs = img.childNodes;
for (var i = childs.length - 1; i >= 0; i--) {
img.removeChild(childs[i]);
}
}
const dataImg = new Image()
dataImg.style.height = "500px";
dataImg.style.width = "100%";
dataImg.src = canvas.toDataURL('image/png', 1.0); //将图片转为base64, 0-1 表示清晰度,得到图片的base64编码数据
document.querySelector('#downloadImg').appendChild(dataImg);
let blob_ = this.dataURLtoBlob(dataImg.src)
const alink = document.querySelector("#imgA");
alink.href = window.URL.createObjectURL(blob_);
alink.download = "map.png";
// alink.onclick = () => {
// canvas.toBlob(function (blob) {
// saveAs(blob, 'map.png');
// });
// };
})
},
dataURLtoBlob(dataurl) {
var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
return new Blob([u8arr], { type: mime });
},
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