vue项目加水印

 1.封装一个waterMark.js文件，可以放在utils下；

let watermark = {}
 
let setWatermark = (str) => {
  let id = '1.23452384164.123412415'
 
  if (document.getElementById(id) !== null) {
    document.body.removeChild(document.getElementById(id))
  }
 
  let can = document.createElement('canvas')
  can.width = 400
  can.height = 300
 
  let cans = can.getContext('2d')
  cans.rotate(-20 * Math.PI / 180)
  cans.font = '20px Vedana'
  cans.fillStyle = 'rgba(200, 200, 200, 0.40)'
  cans.textAlign = 'left'
  cans.textBaseline = 'Middle'
  cans.fillText(str, can.width / 3, can.height / 2)
 
  let div = document.createElement('div')
  div.id = id
  div.style.pointerEvents = 'none'
  div.style.top = '70px'
  div.style.left = '30px'
  div.style.position = 'fixed'
  div.style.zIndex = '100000'
  div.style.width = document.documentElement.clientWidth - 100 + 'px'
  div.style.height = document.documentElement.clientHeight - 100 + '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)
  }
}

const outWatermark = (id) => {
  if (document.getElementById(id) !== null) {
    const div = document.getElementById(id)
    div.style.display = 'none'
  }
}

watermark.out = () => {
  const str = '1.23452384164.123412415'
  outWatermark(str)
}
 
export default watermark

2.在main.js或者入口文件里引入waterMark.js;

import warterMark from "@/utils/warterMark";

3.使用：

warterMark.set("显示的水印内容");

 取消水印：

warterMark.out();

或者

warterMark.set("");