打印vue项目页面或页面中的部分节点

1、应用场景

        在vue项目开发中，一般的产品参数、检测报告都需要提供可打印功能。甚至有可能需要指定内容进行打印。本示例是演示的是指定内容，并拼接成页面进行页面打印，示例中的print.js插件来源于网络。其余为本人原创。

2、print.js 插件

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.noPrint ? this.options.noPrint : '.no-print') +
      '{display:none;}</style>'
    return str
  },
  getHtml: function () {
    var inputs = document.querySelectorAll('input')
    var textareas = document.querySelectorAll('textarea')
    var selects = document.querySelectorAll('select')
    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')
            }
          }
        }
      }
    }
    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:0;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 _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

3、在项目中安装print.js插件

import Print from "@/utils/print";
Vue.use(Print)

4、在项目中使用，打印指定内容

   创建print.vue打印模板，并在需要打印的页面引入并注册

import iPrintDom from './print'

components: {iPrintDom},

<i-print-dom  style="" ref="printDom"></i-print-dom>

   指定要打印的vue内容

<el-collapse-item name="1" ref="baseInfo">
    <!-- 代码块  -->
</el-collapse-item>
<el-collapse-item name="2"  ref="industryInfo">
    <!-- 代码块  -->
</el-collapse-item>
<el-collapse-item name="3"  ref="industryCode">
    <!-- 代码块  -->
</el-collapse-item>
<el-button type="default" size="mini" @click="intPrintDom">打印</el-button>

   

    /**
     *  @actions:  打印表单中部分信息
     *  @content:
     *  @params:
     *          <参数名称>  参数标题  参数类型    默认值
    **/
    intPrintDom(){
      let baseInfo = this.$refs['baseInfo'];
      let industryInfo =  this.$refs['industryInfo'];
      let industryCode = this.$refs['industryCode'];
      let doms = [(baseInfo.$el).cloneNode(true),(industryInfo.$el).cloneNode(true),(industryCode.$el).cloneNode(true)]
      this.$nextTick(()=>{
        this.$refs['printDom'].onPrint(doms)
      })

    },

 print.vue 打印模板

<template>
  <div ref="print">
    <h4 style="text-align:center">打印模板</h4>
    <div ref="print-main">

    </div>
    <div class="print-seal">
      <ul>
        <li><span>盖章:</span></li>
        <li><span>日期:</span></li>
      </ul>
    </div>
  </div>
</template>
<script>
export default {
  name:"printForm",
  data(){
    return{
    }
  },
  mounted(){
  },
  computed:{
  },
  methods:{
    /**
     *  @actions:   打印节点
     *  @content:
     *  @params:
     *          <参数名称>  参数标题  参数类型    默认值
    **/
    onPrint(doms){
      let bodydom = this.$refs['print-main'];
      doms.map(item=>{
        bodydom.appendChild(item);
      })

      this.$nextTick(()=>{
        this.$print(this.$refs['print'])
      })
    }
  }

}
</script>
<style>
ul,lo{
  list-style: none;
  margin: 0;
  padding: 0;
}
.print-seal{
  text-align: right;
}
.print-seal span{
  line-height: 26px;
  margin-right: 100px;
  display: inline-block;
  width:80px;
  text-align: right;
}
</style>