1.waterMark.js

'use strict'
const watermark = {}
const setWatermark = (str) => {
  const id = '7.432756475.689573874'
  if (document.getElementById(id) !== null) {
    document.body.removeChild(document.getElementById(id))
  }
  const can = document.createElement('canvas')
  can.width = 350
  can.height = 130
  const cans = can.getContext('2d')
  cans.rotate(-20 * Math.PI / 180)
  cans.font = '18px Vedana'
  cans.fillStyle = 'rgba(0,0,0,0.06)'
  cans.textAlign = 'left'
  cans.textBaseline = 'Middle'
  cans.fillText(str, can.width / 20, can.height)
  const div = document.createElement('div')
  div.id = id
  div.style.pointerEvents = 'none'
  div.style.top = '3px'
  div.style.left = '0px'
  div.style.position = 'fixed'
  div.style.zIndex = '0'
  div.style.width = document.documentElement.clientWidth + 'px'
  div.style.height = document.documentElement.clientHeight + 'px'
  div.style.background = 'url(' + can.toDataURL('image/png') + ') left top repeat'
  document.body.appendChild(div)
  return id
}

// 该方法只允许调用一次
watermark.set = (str) => {
  let id = setWatermark(str)
  setInterval(() => {
    if (document.getElementById(id) === null) {
      id = setWatermark(str)
    }
  }, 500)
  window.onresize = () => {
    setWatermark(str)
  }
}
let outWatermark = (id) => {
  if (document.getElementById(id) !== null) {
    const div = document.getElementById(id)
    div.style.display = 'none'
  }
}
/**
 *  该方法只允许调用一次
 *  @param:
 *  @text == 水印内容
 *  @sourceBody == 水印添加在哪里，不传就是body
 * */
watermark.out = () => {
  let id = '7.432756475.689573874'
  outWatermark(id)
}
export default watermark;

2.App.vue页面全局引入

  //页面
  <div class="navbar" ref="container">
  ...
  </div>

 //在mounted中调用
  mounted() {
  let date = new Date();
   this.userName = ‘名称’
   this.dateTime = this.dateFormat(new Date(date))
   Watermark.set(this.userName + ' ' + this.dateTime, this.$refs.container);
  },
  //删除水印
   Watermark.out()

  methods:{
    // 格式化时间(水印需要时间可以用这个格式化方法)
    dateFormat(date) {
      //获取年月日，时间
      var year = date.getFullYear();
      var mon =
        date.getMonth() + 1 < 10
          ? "0" + (date.getMonth() + 1)
          : date.getMonth() + 1;
      var data = date.getDate() < 10 ? "0" + date.getDate() : date.getDate();
      var hour = date.getHours() < 10 ? "0" + date.getHours() : date.getHours();
      var min =
        date.getMinutes() < 10 ? "0" + date.getMinutes() : date.getMinutes();
      var seon =
        date.getSeconds() < 10 ? "0" + date.getSeconds() : date.getSeconds();

      var newDate =
        year + "-" + mon + "-" + data + " " + hour + ":" + min + ":" + seon;
      return newDate;
    },
  }

3.局部引入参考全局引入，根据自己需求放在需要的页面