基于vue的架构中，在页面上增加水印，代码如下。
watermark.js
'use strict'
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 = 150
can.height = 120
let cans = can.getContext('2d')
cans.rotate(-20 * Math.PI / 180)
cans.font = '20px Vedana'
cans.fillStyle = 'rgba(200, 200, 200, 0.20)'
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 = '0px'
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)
}
}
export default watermark
用法如下：
在App.vue文件中，导入该文件
import Watermark from './watermark'
然后在mounted函数中调用
mounted: function () {
Watermark.set("水印内容")
}
