vue+element-ui集成随机验证码+用户名+密码的form表单验证功能

在登入页面，我们往往需要通过输入验证码才能进行登入，那我们下面就详讲一下在vue项目中如何配合element-ui实现这个功能

第一步：自定义一个生产随机验证码的组件，其本质是使用canvas绘制，详细代码如下：

<template>
 <div class="s-canvas">
 <canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas>
 </div>
</template>
<script>
export default {
 name: 'SIdentify',
 props: {
 identifyCode: {
  type: String,
  default: '1234'
 },
 fontSizeMin: {
  type: Number,
  default: 16
 },
 fontSizeMax: {
  type: Number,
  default: 40
 },
 backgroundColorMin: {
  type: Number,
  default: 180
 },
 backgroundColorMax: {
  type: Number,
  default: 240
 },
 colorMin: {
  type: Number,
  default: 50
 },
 colorMax: {
  type: Number,
  default: 160
 },
 lineColorMin: {
  type: Number,
  default: 40
 },
 lineColorMax: {
  type: Number,
  default: 180
 },
 dotColorMin: {
  type: Number,
  default: 0
 },
 dotColorMax: {
  type: Number,
  default: 255
 },
 contentWidth: {
  type: Number,
  default: 112
 },
 contentHeight: {
  type: Number,
  default: 38
 }
 },
 methods: {
 // 生成一个随机数
 randomNum(min, max) {
  return Math.floor(Math.random() * (max - min) + min)
 },
 // 生成一个随机的颜色
 randomColor(min, max) {
  var r = this.randomNum(min, max)
  var g = this.randomNum(min, max)
  var b = this.randomNum(min, max)
  return 'rgb(' + r + ',' + g + ',' + b + ')'
 },
 drawPic() {
  var canvas = document.getElementById('s-canvas')
  var ctx = canvas.getContext('2d')
  ctx.textBaseline = 'bottom'
  // 绘制背景
  ctx.fillStyle = this.randomColor(
  this.backgroundColorMin,
  this.backgroundColorMax
  )
  ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
  // 绘制文字
  for (let i = 0; i < this.identifyCode.length; i++) {
  this.drawText(ctx, this.identifyCode[i], i)
  }
  this.drawLine(ctx)
  this.drawDot(ctx)
 },
 drawText(ctx, txt, i) {
  ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax)
  ctx.font =
  this.randomNum(this.fontSizeMin, this.fontSizeMax) + 'px SimHei'
  var x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1))
  var y = this.randomNum(this.fontSizeMax, this.contentHeight - 5)
  var deg = this.randomNum(-45, 45)
  // 修改坐标原点和旋转角度
  ctx.translate(x, y)
  ctx.rotate(deg * Math.PI / 180)
  ctx.fillText(txt, 0, 0)
  // 恢复坐标原点和旋转角度
  ctx.rotate(-deg * Math.PI / 180)
  ctx.translate(-x, -y)
 },
 drawLine(ctx) {
  // 绘制干扰线
  for (let i = 0; i < 8; i++) {
  ctx.strokeStyle = this.randomColor(
   this.lineColorMin,
   this.lineColorMax
  )
  ctx.beginPath()
  ctx.moveTo(
   this.randomNum(0, this.contentWidth),
   this.randomNum(0, this.contentHeight)
  )
  ctx.lineTo(
   this.randomNum(0, this.contentWidth),
   this.randomNum(0, this.contentHeight)
  )
  ctx.stroke()
  }
 },
 drawDot(ctx) {
  // 绘制干扰点
  for (let i = 0; i < 100; i++) {
  ctx.fillStyle = this.randomColor(0, 255)
  ctx.beginPath()
  ctx.arc(
   this.randomNum(0, this.contentWidth),
   this.randomNum(0, this.contentHeight),
   1,
   0,
   2 * Math.PI
  )
  ctx.fill()
  }
 }
 },
 watch: {
 identifyCode() {
  this.drawPic()
 }
 },
 mounted() {
 this.drawPic()
 }
}
</script>

第二步：使用该组件：

我们首先新建一个vue组件，在该组件进行布局，其中还包括用户名和密码的验证（这只是前端的简单验证，真实项目中还需要请求登入接口进行后端验证）

<template>
 <el-form class="login-form" status-icon :rules="loginRules" ref="loginForm" :model="loginForm" label-width="0">
 <el-form-item prop="username">
  <el-input size="small" @keyup.enter.native="handleLogin" v-model="loginForm.username" auto-complete="off" placeholder="请输入用户名">
  <i slot="prefix" class="icon-yonghu"></i>
  </el-input>
 </el-form-item>
 <el-form-item prop="password">
  <el-input size="small" @keyup.enter.native="handleLogin" :type="passwordType" v-model="loginForm.password" auto-complete="off" placeholder="请输入密码">
  <i class="el-icon-view el-input__icon" :style="fontstyle" slot="suffix" @click="showPassword"></i>
  <i slot="prefix" class="icon-mima"></i>
  </el-input>
 </el-form-item>
 <el-form-item prop="verifycode">
  <!-- 注意：prop与input绑定的值一定要一致，否则验证规则中的value会报undefined，因为value即为绑定的input输入值 -->
  <el-input v-model="loginForm.verifycode" placeholder="请输入验证码" class="identifyinput"></el-input>
 </el-form-item>
 <el-form-item>
  <div class="identifybox">
  <div @click="refreshCode">
   <s-identify :identifyCode="identifyCode"></s-identify>
  </div>
  <el-button @click="refreshCode" type='text' class="textbtn">看不清，换一张</el-button>
  </div>
 </el-form-item>
 <el-checkbox v-model="checked">记住账号</el-checkbox>
 <el-form-item>
  <el-button type="primary" size="small" @click.native.prevent="handleLogin" class="login-submit">登录</el-button>
 </el-form-item>
 </el-form>
</template>

第三步：生产随机码与进行登入验证

<script>
import { isvalidUsername } from '@/utils/validate'
import SIdentify from '@/components/identify/identify.vue'
export default {
 name: 'userlogin',
 data() {
 // 用户名自定义验证规则
 const validateUsername = (rule, value, callback) => {
  if (!isvalidUsername(value)) {
  callback(new Error('请输入正确的用户名'))
  } else {
  console.log('user', value)
  callback()
  }
 }
 // 验证码自定义验证规则
 const validateVerifycode = (rule, value, callback) => {
  if (value === '') {
  callback(new Error('请输入验证码'))
  } else if (value !== this.identifyCode) {
  console.log('validateVerifycode:', value)
  callback(new Error('验证码不正确!'))
  } else {
  callback()
  }
 }
 return {
  fontstyle: {
  },
  loginForm: {
  username: 'admin',
  password: '123456',
  verifycode: ''
  },
  checked: false,
  identifyCodes: '1234567890',
  identifyCode: '',
  loginRules: { // 绑定在form表单中的验证规则
  username: [
   { required: true, trigger: 'blur', validator: validateUsername }
  ],
  password: [
   { required: true, message: '请输入密码', trigger: 'blur' },
   { min: 6, message: '密码长度最少为6位', trigger: 'blur' }
  ],
  verifycode: [
   { required: true, trigger: 'blur', validator: validateVerifycode }
  ]
  },
  passwordType: 'password'
 }
 },
 components: {
 SIdentify
 },
 created() {
 },
 mounted() {
 // 验证码初始化
 this.identifyCode = ''
 this.makeCode(this.identifyCodes, 4)
 },
 computed: {
 },
 props: [],
 methods: {
 // 通过改变input的type使密码可见
 showPassword() {
  this.fontstyle === '' ? (this.fontstyle = 'color: red') : (this.fontstyle = '') // 改变密码可见按钮颜色
  this.passwordType === ''
  ? (this.passwordType = 'password')
  : (this.passwordType = '')
 },
 // 点击登入按钮
 handleLogin() {
  this.$refs.loginForm.validate(valid => {
  if (valid) {
   this.$store.dispatch('Login', this.loginForm).then(res => {
   this.$router.push({ path: '/dashboard/dashboard' })
   })
  }
  })
 },
 // 生成随机数
 randomNum(min, max) {
  return Math.floor(Math.random() * (max - min) + min)
 },
 // 切换验证码
 refreshCode() {
  this.identifyCode = ''
  this.makeCode(this.identifyCodes, 4)
 },
 // 生成四位随机验证码
 makeCode(o, l) {
  for (let i = 0; i < l; i++) {
  this.identifyCode += this.identifyCodes[
   this.randomNum(0, this.identifyCodes.length)
  ]
  }
  console.log(this.identifyCode)
 }
 }
}
</script>
<style scoped>
.identifybox{
 display: flex;
 justify-content: space-between;
 margin-top:7px;
}
.iconstyle{
 color:#409EFF;
}
</style>

最后的效果如下，当我们输入之后鼠标失去焦点就会进行验证：