欢迎关注微信公众号：【 全栈攻略 】

众所周知，前端打印的API只有window.print()，而我们要实现自动打印和批量打印，甚至连获取本地电脑的打印机有哪些都无法获取到。难道，前端对此真的无能为力吗？答案是 否定 ！

Lodop 由此诞生，有人说她是Web打印控件的“终结者”，因为接触“她”后再不想别的“她”。 那我们就来揭开这神秘都面纱！

一，首先我们要改造Lodpo的源代码文件为适合Vue/React/Angular等框架如下：

LodopFuncs.js

var CreatedOKLodop7766 = null, CLodopIsLocal;//====判断是否需要 Web打印服务CLodop:===
//===(不支持插件的浏览器版本需要用它)===
export function needCLodop() {try {var ua = navigator.userAgent;if (ua.match(/Windows\sPhone/i))return true;if (ua.match(/iPhone|iPod|iPad/i))return true;if (ua.match(/Android/i))return true;if (ua.match(/Edge\D?\d+/i))return true;var verTrident = ua.match(/Trident\D?\d+/i);var verIE = ua.match(/MSIE\D?\d+/i);var verOPR = ua.match(/OPR\D?\d+/i);var verFF = ua.match(/Firefox\D?\d+/i);var x64 = ua.match(/x64/i);if ((!verTrident) && (!verIE) && (x64))return true;else if (verFF) {verFF = verFF[0].match(/\d+/);if ((verFF[0] >= 41) || (x64))return true;} else if (verOPR) {verOPR = verOPR[0].match(/\d+/);if (verOPR[0] >= 32)return true;} else if ((!verTrident) && (!verIE)) {var verChrome = ua.match(/Chrome\D?\d+/i);if (verChrome) {verChrome = verChrome[0].match(/\d+/);if (verChrome[0] >= 41)return true;}}return false;} catch (err) {return true;}
}//====页面引用CLodop云打印必须的JS文件,用双端口(8000和18000）避免其中某个被占用：====
if (needCLodop()) {var src1 = "http://localhost:8000/CLodopfuncs.js?priority=1";var src2 = "http://localhost:18000/CLodopfuncs.js?priority=0";var head = document.head || document.getElementsByTagName("head")[0] || document.documentElement;var oscript = document.createElement("script");oscript.src = src1;head.insertBefore(oscript, head.firstChild);oscript = document.createElement("script");oscript.src = src2;head.insertBefore(oscript, head.firstChild);CLodopIsLocal = !!((src1 + src2).match(/\/\/localho|\/\/127.0.0./i));
}//====获取LODOP对象的主过程：====
export function getLodop(oOBJECT, oEMBED) {var strHtmInstall = "<br><font color='#FF00FF'>打印控件未安装!点击这里<a href='install_lodop32.exe' target='_self'>执行安装</a>,安装后请刷新页面或重新进入。</font>";var strHtmUpdate = "<br><font color='#FF00FF'>打印控件需要升级!点击这里<a href='install_lodop32.exe' target='_self'>执行升级</a>,升级后请重新进入。</font>";var strHtm64_Install = "<br><font color='#FF00FF'>打印控件未安装!点击这里<a href='install_lodop64.exe' target='_self'>执行安装</a>,安装后请刷新页面或重新进入。</font>";var strHtm64_Update = "<br><font color='#FF00FF'>打印控件需要升级!点击这里<a href='install_lodop64.exe' target='_self'>执行升级</a>,升级后请重新进入。</font>";var strHtmFireFox = "<br><br><font color='#FF00FF'>（注意：如曾安装过Lodop旧版附件npActiveXPLugin,请在【工具】->【附加组件】->【扩展】中先卸它）</font>";var strHtmChrome = "<br><br><font color='#FF00FF'>(如果此前正常，仅因浏览器升级或重安装而出问题，需重新执行以上安装）</font>";var strCLodopInstall_1 = "<br><font color='#FF00FF'>Web打印服务CLodop未安装启动，点击这里<a href='CLodop_Setup_for_Win32NT.exe' target='_self'>下载执行安装</a>";var strCLodopInstall_2 = "<br>（若此前已安装过，可<a href='CLodop.protocol:setup' target='_self'>点这里直接再次启动</a>）";var strCLodopInstall_3 = "，成功后请刷新本页面。</font>";var strCLodopUpdate = "<br><font color='#FF00FF'>Web打印服务CLodop需升级!点击这里<a href='CLodop_Setup_for_Win32NT.exe' target='_self'>执行升级</a>,升级后请刷新页面。</font>";var LODOP;try {var ua = navigator.userAgent;var isIE = !!(ua.match(/MSIE/i)) || !!(ua.match(/Trident/i));if (needCLodop()) {try {LODOP = getCLodop();} catch (err) {}if (!LODOP && document.readyState !== "complete") {alert("网页还没下载完毕，请稍等一下再操作.");return;}if (!LODOP) {//document.body.innerHTML = strCLodopInstall_1 + (CLodopIsLocal ? strCLodopInstall_2 : "") + strCLodopInstall_3 + document.body.innerHTML;                return;} else {if (CLODOP.CVERSION < "3.0.8.3") {document.body.innerHTML = strCLodopUpdate + document.body.innerHTML;}if (oEMBED && oEMBED.parentNode)oEMBED.parentNode.removeChild(oEMBED);if (oOBJECT && oOBJECT.parentNode)oOBJECT.parentNode.removeChild(oOBJECT);}} else {var is64IE = isIE && !!(ua.match(/x64/i));//=====如果页面有Lodop就直接使用，没有则新建:==========if (oOBJECT || oEMBED) {if (isIE)LODOP = oOBJECT;elseLODOP = oEMBED;} else if (!CreatedOKLodop7766) {LODOP = document.createElement("object");LODOP.setAttribute("width", 0);LODOP.setAttribute("height", 0);LODOP.setAttribute("style", "position:absolute;left:0px;top:-100px;width:0px;height:0px;");if (isIE)LODOP.setAttribute("classid", "clsid:2105C259-1E0C-4534-8141-A753534CB4CA");elseLODOP.setAttribute("type", "application/x-print-lodop");document.documentElement.appendChild(LODOP);CreatedOKLodop7766 = LODOP;} elseLODOP = CreatedOKLodop7766;//=====Lodop插件未安装时提示下载地址:==========if ((!LODOP) || (!LODOP.VERSION)) {if (ua.indexOf('Chrome') >= 0)document.body.innerHTML = strHtmChrome + document.body.innerHTML;if (ua.indexOf('Firefox') >= 0)document.body.innerHTML = strHtmFireFox + document.body.innerHTML;document.body.innerHTML = (is64IE ? strHtm64_Install : strHtmInstall) + document.body.innerHTML;return LODOP;}}if (LODOP.VERSION < "6.2.2.6") {if (!needCLodop())document.body.innerHTML = (is64IE ? strHtm64_Update : strHtmUpdate) + document.body.innerHTML;}//===如下空白位置适合调用统一功能(如注册语句、语言选择等):==// 添加注册码，打印就不会出现 “本页由lodop试用版输出 ”    LODOP.SET_LICENSES("","XXXXX","XXXX","");//=======================================================return LODOP;} catch (err) {alert("getLodop出错:" + err);}
}

二，获取本地电脑连接都有哪些打印机

先上效果图：

代码如下：

 // 先导入getLodop方法
import { getLodop } from "plugin/LodopFuncs.js";// 获取打印机列表getPrintList() {let LODOP = getLodop();if (!LODOP)return// 获取打印机个数let count = LODOP.GET_PRINTER_COUNT()let printValue = LODOP.GET_PRINTER_NAME(-1) //获取默认打印机this.printList = Array(count).fill(null).map((...args) => {if (printValue === LODOP.GET_PRINTER_NAME(args[1])){this.printDefault = args[1]}return {value: args[1], // args[1]为数组索引label: LODOP.GET_PRINTER_NAME(args[1]) // 获取打印机名称}})},

三，实现自动打印和批量打印

自动打印没法上效果图了，自己试一下就可以了 ^ _ ^

不过可以上，我们仓储系统的场景图：

代码如下：

 // 多选handleSelectionChange(val) {this.multipleSelection = val;},// 批量打印async batchPrint() {if(!this.multipleSelection.length){this.$utils.commonUtils.tip('请选择','warning')return}for await(const key of this.multipleSelection) {this.getPrintData(key.printUrl)}},// 打印handleReview(index, row) {this.getPrintData(row.printUrl)},// 获取面单信息数组数据async getPrintData(url) {if(url) {this.printUrlList = url.split(';')this.printInfo()}},// 打印面单 async printInfo() {for await (const item of this.printUrlList) {this.printEveryItem(item)}},// 打印每项printEveryItem(item) {let self = this;let LODOP = getLodop(); //调用getLodop获取LODOP对象return new Promise(function (resolve) {setTimeout(() => {LODOP.PRINT_INIT("");let strStyleCSS = `<style type='text/css' rel='stylesheet'>.img1{display:block;margin:10px;width:360;height:360}</style>`let html = `<head>${strStyleCSS}</head><body><div class='print-card'><img src=${item} class='img1' /></div><body>`LODOP.ADD_PRINT_HTM(0,0,380,380,html);LODOP.SET_PRINT_PAGESIZE(1,1000,1000,"");   LODOP.PRINT();}, 1000);});}  

单个打印和批量打印实现了，自动打印就简单了，满足条件调用打印方法即可，如仓储系统实际业务需求，当播种完成自动打印

至此，前端实现了自动打印 批量打印功能，更多功能可自行扩展，Lodop 等你探索！

PS：未来的你，一定会感谢今天拼命努力的自己！