前言：在Vue中利用自带的页面打印是打印不出ECharts图表的，原因是获取不到ECharts插件的css节点。打印出来的结果会是空白。经过参考了网上的多篇文档，总结步骤阐述了一下，希望为大家提供一点小小帮助。
1.在Vue项目中某个文件夹下创建一个print.js的文件，文件内容为：
// 打印类属性、方法定义
/* eslint-disable */
const Print = function (dom, options) {
if (!(this instanceof Print)) return new Print(dom, options);
this.options = this.extend({
'noPrint': '.no-print'
}, options);
if ((typeof dom) === "string") {
this.dom = document.querySelector(dom);
} else {
this.isDOM(dom)
this.dom = this.isDOM(dom) ? dom : dom.$el;
}
this.init();
};
Print.prototype = {
init: function () {
var content = this.getStyle() + this.getHtml();
this.writeIframe(content);
},
extend: function (obj, obj2) {
for (var k in obj2) {
obj[k] = obj2[k];
}
return obj;
},
getStyle: function () {
var str = "",
styles = document.querySelectorAll('style,link');
for (var i = 0; i < styles.length; i++) {
str += styles[i].outerHTML;
}
str += "<style>" + (this.options.notPrint ? this.options.notPrint : '.no-print') + "{display:none;}</style>";
str += "<style>.results{width:100%!important;} .result .title{width:100%;}</style>";
return str;
},
getHtml: function () {
var inputs = document.querySelectorAll('input');
var textareas = document.querySelectorAll('textarea');
var selects = document.querySelectorAll('select');
var canvass = document.querySelectorAll('canvas');
for (var k = 0; k < inputs.length; k++) {
if (inputs[k].type == "checkbox" || inputs[k].type == "radio") {
if (inputs[k].checked == true) {
inputs[k].setAttribute('checked', "checked")
} else {
inputs[k].removeAttribute('checked')
}
} else if (inputs[k].type == "text") {
inputs[k].setAttribute('value', inputs[k].value)
} else {
inputs[k].setAttribute('value', inputs[k].value)
}
}
for (var k2 = 0; k2 < textareas.length; k2++) {
if (textareas[k2].type == 'textarea') {
textareas[k2].innerHTML = textareas[k2].value
}
}
for (var k3 = 0; k3 < selects.length; k3++) {
if (selects[k3].type == 'select-one') {
var child = selects[k3].children;
for (var i in child) {
if (child[i].tagName == 'OPTION') {
if (child[i].selected == true) {
child[i].setAttribute('selected', "selected")
} else {
child[i].removeAttribute('selected')
}
}
}
}
}
//canvass echars图表转为图片
for (var k4 = 0; k4 < canvass.length; k4++) {
var imageURL = canvass[k4].toDataURL("image/png");
var img = document.createElement("img");
img.src = imageURL;
img.setAttribute('style', 'max-width: 100%;');
img.className = 'isNeedRemove'
// canvass[k4].style.display = 'none'
// canvass[k4].parentNode.style.width = '100%'
// canvass[k4].parentNode.style.textAlign = 'center'
canvass[k4].parentNode.insertBefore(img,canvass[k4].nextElementSibling);
}
//做分页
//style="page-break-after: always"
var pages = document.querySelectorAll('.content');
for (var k5 = 0; k5 < pages.length; k5++) {
pages[k5].setAttribute('style', 'page-break-after: always');
}
return this.dom.outerHTML;
},
writeIframe: function (content) {
var w, doc, iframe = document.createElement('iframe'),
f = document.body.appendChild(iframe);
iframe.id = "myIframe";
//iframe.style = "position:absolute;width:0;height:0;top:-10px;left:-10px;";
iframe.setAttribute('style', 'position:absolute;width:' + document.querySelector('#seven').clientWidth + 'px;height:0;top:-10px;left:-10px;');
w = f.contentWindow || f.contentDocument;
doc = f.contentDocument || f.contentWindow.document;
doc.open();
doc.write(content);
doc.close();
var removes = document.querySelectorAll('.isNeedRemove');
for (var k = 0; k < removes.length; k++) {
removes[k].parentNode.removeChild(removes[k]);
}
var _this = this
iframe.onload = function(){
_this.toPrint(w);
setTimeout(function () {
document.body.removeChild(iframe)
}, 100)
}
},
toPrint: function (frameWindow) {
try {
setTimeout(function () {
frameWindow.focus();
try {
if (!frameWindow.document.execCommand('print', false, null)) {
frameWindow.print();
}
} catch (e) {
frameWindow.print();
}
frameWindow.close();
}, 10);
} catch (err) {
console.log('err', err);
}
},
isDOM: (typeof HTMLElement === 'object') ?
function (obj) {
return obj instanceof HTMLElement;
} :
function (obj) {
return obj && typeof obj === 'object' && obj.nodeType === 1 && typeof obj.nodeName === 'string';
}
};
const MyPlugin = {}
MyPlugin.install = function (Vue, options) {
// 4. 添加实例方法
Vue.prototype.$print = Print
}
export default MyPlugin
2.在main.js中要进行注册发现，可供全局使用。下面是我的代码
import print from './http/print'
Vue.use(print)
3.在ECharts页面中，自定义自己的打印方法
<el-button type="info" @click="printTest()" plain>打印</el-button> //打印按钮
printTest(){ //打印方法
this.$print(this.$refs.print,{'notPrint':'.el-button, .el-select'})
}
4.特别注意事项：
在print.js中 var pages = document.querySelectorAll(’.content’);与document.querySelector(’#seven’).clientWidth + ‘px;height:0;top:-10px;left:-10px;’);
的.content与#seven是要修改自己页面自定义的选择器。
这里贴上我的选择的器位置，大家一定要注意上面两个选择器在div中的嵌套关系
<template>
<div class="content" id="print" ref="print">
<div class="block">
<el-date-picker
v-model="value2"
type="datetimerange"
format="yyyy-MM-dd HH:mm:ss"
:picker-options="pickerOptions"
range-separator="至"
start-placeholder="开始日期"
end-placeholder="结束日期"
>
</el-date-picker>
<el-button type="info" @click="dt()">查询</el-button>
<el-button type="info" @click="printTest()" plain>打印</el-button>
</div>
<!--<p class="prompt_p"> 动态数据测试</p>-->
<div style="height:580px;" id="seven">
</div>
</div>
</template>
参考的文档：
https://blog.csdn.net/shishuwei111/article/details/94167974#comments
对他也表示感谢！
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版权声明：本文为CSDN博主「大帅国」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/qq_43251032/article/details/101281839
