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(&#