// 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.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')
            }
          }
        }
      }
    }
    // 包裹要打印的元素
    // fix: https://github.com/xyl66/vuePlugs_printjs/issues/36
    return this.wrapperRefDom(this.dom).outerHTML;
  },
  // 向父级元素循环,包裹当前需要打印的元素
  // 防止根级别开头的 css 选择器不生效
  wrapperRefDom: function (refDom) {
    let prevDom = null
    let currDom = refDom
    while (currDom && currDom.tagName.toLowerCase() !== 'body') {
      if (prevDom) {
        let element = currDom.cloneNode(false)
        element.appendChild(prevDom)
        prevDom = element
      } else {
        prevDom = currDom.cloneNode(true)
      }

      currDom = currDom.parentElement
    }

    return currDom.tagName.toLowerCase() === 'body' ? currDom : prevDom
  },

  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

2、main.js中进行引入

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

3、使用

<div class="printContainer clearfix" ref="samplePdf">
    <div class="prinfLeft fl">
      <img :src="qrcode" alt="codePic" />
      <p>扫码查询样品信息</p>
    </div>
    <ul class="printRight fr">
      <li><label>样品&nbsp;&nbsp;&nbsp;&nbsp;ID:</label><span>{{ TaskNum  }}</span></li>
      <li><label>任务名称:</label><span>{{ TaskName  }}</span></li>
      <li><label>检测项目:</label><span>{{ DetectionTaskItems }}</span></li>
      <li><label>委托人:</label><span>{{ SamplePerson }}</span></li>
      <li><label>所属部门:</label><span>{{ CreatedDepartmentName }}</span></li>
      <li><label>样品所有人:</label><span>{{ RelationUserName }}</span></li>
      <li><label>平行样品:</label><span>{{ SampleNum }}</span></li>
      <li><label>样品原号:</label><span>{{ repsampleSign }}</span></li>
      <li><label>送样日期:</label><span>{{ createTime }}</span></li>
    </ul>
  </div>
  <span slot="footer" class="dialog-footer no-print">
      <el-button type="info" @click="closeSamplePdf">返回</el-button>
      <el-button type="info" @click="samplePrint">保存PDF</el-button>
      <el-button type="info" @click="samplePrint">打印</el-button>
  </span>
 
 
 methods: {
 	// 打印
    samplePrint() {
        this.$print(this.$refs.samplePdf)
    },
 }
 

4、备注

对于不想打印的内容添加 .no-print 类