vue3 前端实现pdf打印预览 printjs

1. 在utils建print.ts文件

   interface PrintFunction {
   extendOptions: Function;
   getStyle: Function;
   setDomHeight: Function;
   toPrint: Function;
   }

   const Print = function (dom, options?: object): PrintFunction {
   options = options || {};
   // @ts-expect-error
   if (!(this instanceof Print)) return new Print(dom, options);
   this.conf = {
   styleStr: "",
   // Elements that need to dynamically get and set the height
   setDomHeightArr: [],
   // Callback before printing
   printBeforeFn: null,
   // Callback after printing
   printDoneCallBack: null
   };
   for (const key in this.conf) {
   // eslint-disable-next-line no-prototype-builtins
   if (key && options.hasOwnProperty(key)) {
   this.conf[key] = options[key];
   }
   }
   if (typeof dom === "string") {
   this.dom = document.querySelector(dom);
   } else {
   this.dom = this.isDOM(dom) ? dom : dom.$el;
   }
   if (this.conf.setDomHeightArr && this.conf.setDomHeightArr.length) {
   this.setDomHeight(this.conf.setDomHeightArr);
   }
   this.init();
   };

   Print.prototype = {
   /**
   * init
   /
   init: function (): void {
   const content = this.getStyle() + this.getHtml();
   this.writeIframe(content);
   },
   /*
   * Configuration property extension
   * @param {Object} obj
   * @param {Object} obj2
   /
   extendOptions: function <T>(obj, obj2: T): T {
   for (const k in obj2) {
   obj[k] = obj2[k];
   }
   return obj;
   },
   /*
   Copy all styles of the original page
   */
   getStyle: function (): string {
   let str = "";
   const styles: NodeListOf<Element> = document.querySelectorAll("style,link");
   for (let i = 0; i < styles.length; i++) {
   str += styles[i].outerHTML;
   }
   str += <style>.no-print{display:none;}${this.conf.styleStr}</style>;
   return str;
   },
   // form assignment
   getHtml: function (): Element {
   const inputs = document.querySelectorAll("input");
   const selects = document.querySelectorAll("select");
   const textareas = document.querySelectorAll("textarea");
   const canvass = document.querySelectorAll("canvas");

    for (let 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 (let k2 = 0; k2 < textareas.length; k2++) {
      if (textareas[k2].type == "textarea") {
        textareas[k2].innerHTML = textareas[k2].value;
      }
    }
   
    for (let k3 = 0; k3 < selects.length; k3++) {
      if (selects[k3].type == "select-one") {
        const child = selects[k3].children;
        for (const i in child) {
          if (child[i].tagName == "OPTION") {
            if ((child[i] as any).selected == true) {
              child[i].setAttribute("selected", "selected");
            } else {
              child[i].removeAttribute("selected");
            }
          }
        }
      }
    }
   
    for (let k4 = 0; k4 < canvass.length; k4++) {
      const imageURL = canvass[k4].toDataURL("image/png");
      const img = document.createElement("img");
      img.src = imageURL;
      img.setAttribute("style", "max-width: 100%;");
      img.className = "isNeedRemove";
      canvass[k4].parentNode.insertBefore(img, canvass[k4].nextElementSibling);
    }
   
    return this.dom.outerHTML;
   

   },
   /**
   create iframe
   */
   writeIframe: function (content) {
   let w: Document | Window;
   let doc: Document;
   const iframe: HTMLIFrameElement = document.createElement("iframe");
   const f: HTMLIFrameElement = document.body.appendChild(iframe);
   iframe.id = "myIframe";
   iframe.setAttribute(
   "style",
   "position:absolute;width:0;height:0;top:-10px;left:-10px;"
   );
   // eslint-disable-next-line prefer-const
   w = f.contentWindow || f.contentDocument;
   // eslint-disable-next-line prefer-const
   doc = f.contentDocument || f.contentWindow.document;
   doc.open();
   doc.write(content);
   doc.close();

    const removes = document.querySelectorAll(".isNeedRemove");
    for (let k = 0; k < removes.length; k++) {
      removes[k].parentNode.removeChild(removes[k]);
    }
   
    // eslint-disable-next-line @typescript-eslint/no-this-alias
    const _this = this;
    iframe.onload = function (): void {
      // Before popping, callback
      if (_this.conf.printBeforeFn) {
        _this.conf.printBeforeFn({ doc });
      }
      _this.toPrint(w);
      setTimeout(function () {
        document.body.removeChild(iframe);
        // After popup, callback
        if (_this.conf.printDoneCallBack) {
          _this.conf.printDoneCallBack();
        }
      }, 100);
    };
   

   },
   /**
   Print
   /
   toPrint: function (frameWindow): void {
   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.error(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"
   );
   },
   /*
   * Set the height of the specified dom element by getting the existing height of the dom element and setting
   * @param {Array} arr
   */
   setDomHeight(arr) {
   if (arr && arr.length) {
   arr.forEach(name => {
   const domArr = document.querySelectorAll(name);
   console.log(name, domArr);
   domArr.forEach(dom => {
   dom.style.height = dom.offsetHeight + "px";
   });
   });
   }
   }
   };

   export default Print;

2. .vue页面使用
   html

    <div class="w-full p-1" id="printApply" style="overflow: auto">
      <div class="text-center text-2xl">江苏微导纳米股份有限公司</div>
      <div class="text-center text-xl mb-6 mt-2">
        工具出库单
      </div>
      <div class="flex">
        <div class="flex-1 mb-2">
          <div class="mb-3">事业部：{{ dataSource.chargeDept }}</div>
          <div class="mb-3">班组: {{ dataSource.groupName }}</div>
          <div class="">联系人： ____________________</div>
        </div>
        <div class="flex-1 mb-2">
          <div class="mb-3">申请人：{{ dataSource.applicant }}</div>
          <div class="mb-3">申请部门：{{ dataSource.applicantDept }}</div>
          <div class="">联系电话： _____________________</div>
        </div>
        <div class="flex-1 mb-2">
          <div class="mb-3">工具属性：{{ dataSource.toolProperty }}</div>
          <div class="mb-3">工厂: {{ dataSource.factoryName }}</div>
        </div>
      </div>
      <div class="my-3 w-full">
        <table>
          <colgroup>
            <col width="50" />
            <col width="120" />
            <col width="150" />
            <col width="150" />
            <col width="100" />
            <col width="100" />
            <col width="100" />
            <col width="100" />
          </colgroup>
          <tbody>
            <tr height="32" class="">
              <td class="text-center font-bold">序号</td>
              <td class="text-center font-bold">存货编码</td>
              <td class="text-center font-bold">存货名称</td>
              <td class="text-center font-bold">需求时间</td>
              <td class="text-center font-bold">重要程度</td>
              <td class="text-center font-bold">请购用途</td>
              <td class="text-center font-bold">规格型号</td>
              <!-- <td class="text-center font-bold">工具大类</td> -->
              <td class="text-center font-bold">申领数量</td>
            </tr>
            <template v-for="(item, index) in dataSource.lists">
              <tr height="32">
                <td class="text-center">{{ index+1 }}</td>
                <td class="text-center">{{ item.cInvCode }}</td>
                <td class="text-center">{{ item.cInvName }}</td>
                <td class="text-center">{{ item.demandTime&&item.demandTime.slice(0, 10) }}</td>
                <td class="text-center">{{ item.significance }}</td>
                <td class="text-center">{{ item.purpose }}</td>
                <td class="text-center">{{ item.cInvStd }}</td>
                <!-- <td class="text-center">{{ item.toolType }}</td> -->
                <td class="text-center">{{ item.applicationQty }}</td>
              </tr>
              
            </template>
            <tr height="32">
              <td class="text-center font-bold">合计：</td>
              <td colspan="6" class="text-left"></td>
              <td class="text-center">{{sum}}</td>
            </tr>
            <tr height="65">
              <td colspan="8" class="text-left ">
                备注：
                <br />
                1、请双方确认无误后签字确认，谢谢！
              </td>
            </tr>
          </tbody>
        </table>
      </div>
      <div class="w-4/5 mt-2 flex justify-around">
        <div class="">
          <div class="">发起人签字:</div>
          <div class="mt-2">发起日期:</div>
        </div>
        <div class="">
          <div class="">审批人签字:</div>
          <div class="mt-2">审批日期:</div>
        </div>
      </div>
    </div>
   

css

#printApply {
  display: none;
}
// 设置打印的时候，显示
#printApply {
  @media print {
    display: block;
  }
}

#printApply table {
  border-top: 1px solid #333;
  border-left: 1px solid #333;
  border-spacing: 0;
  background-color: #fff;
  width: 100%;
}
#printApply table td {
  border-bottom: 1px solid #333;
  border-right: 1px solid #333;
  font-size: 14px;
  padding: 5px;
}

ts

import {
  Printer
} from "@element-plus/icons-vue";
import Print from "@/utils/print";

const dataSource = ref({
  chargeDept: "",
  groupName: "",
  applicant: "",
  applicantDept: "",
  toolProperty: "",
  factoryName: "",
  lists: []
})
let sum = 0
const handlePrint = async (row) => {
  sum = 0
  dataSource.value = row
  dataSource.value.lists.forEach((item) => {
    sum += item.applicationQty
  })
  setTimeout(() => {
    Print("#printApply").toPrint;
  },500)
};

注意：在主页面打印 需要给#printApply设置隐藏 设置打印的时候，再显示，即

#printApply {
  display: none;
}
#printApply {
  @media print {
   display: block;
  }
}