纯前端实现加减运算验证码

实现效果

//页面展示

	<template><view class="form-input-item" style="padding:8rpx 22rpx;"><input class="form-input" placeholder="请输入验证码" type="text" maxlength="6" confirm-type="next" placeholder-class="placeholder" name="code" v-model="code"></input>	<view ><div id="v_container" style="width:220rpx;height:82rpx;"></div></view></view></template>

<script>import { gvertify } from '@/common/gvertify'   //引入mounted() {this.verifyCode = new gvertify('v_container')  }//提交表单验证
if (this.code) {const verifyFlag = this.verifyCode.validate(this.code);console.log(verifyFlag);if (!verifyFlag) {this.$u.toast('请输入正确的验证码');return false} }
</script>

封装的插件

function gvertify(options) { // 创建一个图形验证码对象，接收options对象为参数this.options = { // 默认options参数值id: 'canvas', // 容器IdcanvasId: 'verifyCanvas', // canvas的IDwidth: '100%', // 默认canvas宽度height: '100%', // 默认canvas高度type: 'number', // 图形验证码默认类型blend:数字字母混合类型、number:纯数字、letter:纯字母code: ''}if (Object.prototype.toString.call(options) === '[object Object]') { // 判断传入参数类型for (var i in options) { // 根据传入的参数，修改默认参数值this.options[i] = options[i]}} else {this.options.id = options}this.options.numArr = '0,1,2,3,4,5,6,7,8,9'.split(',')this.options.letterArr = getAllLetter()this._init()this.refresh()
}gvertify.prototype = {/** 版本号**/version: '1.0.0',/** 初始化方法**/_init: function() {var con = document.getElementById(this.options.id)var canvas = document.createElement('canvas')// this.options.width = con.offsetWidth > 0 ? con.offsetWidth : '30'// this.options.height = con.offsetHeight > 0 ? con.offsetHeight : '30'this.options.width = con.offsetWidththis.options.height = '40'canvas.id = this.options.canvasIdcanvas.width = this.options.widthcanvas.height = this.options.heightcanvas.style.cursor = 'pointer'canvas.innerHTML = '您的浏览器版本不支持canvas'con.appendChild(canvas)var parent = thiscanvas.onclick = function() {parent.refresh()}},/** 生成验证码**/refresh: function() {var canvas = document.getElementById(this.options.canvasId)if (canvas.getContext) {var ctx = canvas.getContext('2d')}ctx.textBaseline = 'middle'ctx.fillStyle = randomColor(180, 240)ctx.fillRect(0, 0, this.options.width, this.options.height)if (this.options.type === 'blend') { // 判断验证码类型var txtArr = this.options.numArr.concat(this.options.letterArr)} else if (this.options.type === 'number') {// eslint-disable-next-line no-redeclarevar txtArr = this.options.numArr} else {// eslint-disable-next-line no-redeclarevar txtArr = this.options.letterArr}this.options.code = []for (var i = 1; i <= 3; i++) {var txt = txtArr[randomNum(0, txtArr.length)]ctx.font = randomNum(this.options.height, this.options.height) + 'px SimHei' // 随机生成字体大小ctx.fillStyle = randomColor(50, 160) // 随机生成字体颜色ctx.shadowOffsetX = randomNum(-3, 3)ctx.shadowOffsetY = randomNum(-3, 3)ctx.shadowBlur = randomNum(-3, 3)ctx.shadowColor = 'rgba(0, 0, 0, 0.3)'var x = this.options.width / 5 * ivar y = this.options.height / 2var deg = randomNum(-30, 30)/** 设置旋转角度和坐标原点**/ctx.translate(x, y)ctx.rotate(deg * Math.PI / 180)// 中间符号if (i === 2) {const index = randomNum(0, 3)const fuhao = ['+', '-', '*'][index]console.log(fuhao)ctx.fillText(fuhao, 0, 0)this.options.code.push(fuhao)} else {ctx.fillText(txt, 0, 0)this.options.code.push(Number(txt))}/** 恢复旋转角度和坐标原点**/ctx.rotate(-deg * Math.PI / 180)ctx.translate(-x, -y)}/** 绘制干扰线**/// eslint-disable-next-line no-redeclarefor (var i = 0; i < 4; i++) {ctx.strokeStyle = randomColor(40, 180)ctx.beginPath()ctx.moveTo(randomNum(0, this.options.width), randomNum(0, this.options.height))ctx.lineTo(randomNum(0, this.options.width), randomNum(0, this.options.height))ctx.stroke()}/** 绘制干扰点**/// eslint-disable-next-line no-redeclarefor (var i = 0; i < this.options.width / 4; i++) {ctx.fillStyle = randomColor(0, 255)ctx.beginPath()ctx.arc(randomNum(0, this.options.width), randomNum(0, this.options.height), 1, 0, 2 * Math.PI)ctx.fill()}},/** 验证验证码**/validate: function(code) {// eslint-disable-next-line no-redeclarevar code = Number(code)var v_codeif (this.options.code[1] === '-') {v_code = this.options.code[0] - this.options.code[2]} else if (this.options.code[1] === '+') {v_code = this.options.code[0] + this.options.code[2]} else if (this.options.code[1] === '*') {v_code = this.options.code[0] * this.options.code[2]}console.log(this.options.code, v_code, code)if (code === v_code) {return true} else {return false}}
}
/** 生成字母数组**/
function getAllLetter() {var letterStr = 'a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z'return letterStr.split(',')
}
/** 生成一个随机数**/
function randomNum(min, max) {return Math.floor(Math.random() * (max - min) + min)
}
/** 生成一个随机色**/
function randomColor(min, max) {var r = randomNum(min, max)var g = randomNum(min, max)var b = randomNum(min, max)return 'rgb(' + r + ',' + g + ',' + b + ')'
}export {gvertify
}