简单的验证码功能

<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: 20
        },
        fontSizeMax: {
          type: Number,
          default: 35
        },
        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) {
          let r = this.randomNum(min, max)
          let g = this.randomNum(min, max)
          let b = this.randomNum(min, max)
          return 'rgb(' + r + ',' + g + ',' + b + ')'
        },
        drawPic () {
          let canvas = document.getElementById('s-canvas')
          let 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'
          let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1))
          let 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 < 3; 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 < 30; 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>

import SIdentify from './components/identify' //注意引入路径
Vue.use(SIdentify)

<el-form-item label="验证码" prop="sidentify">
        <el-input v-model="loginForm.sidentify" style="width: 50%;float: left;" autocomplete="off" placeholder="请输入右侧验证码" />
        <div class="coderight" @click="refreshCode">
          <SIdentify :identifyCode="identifyCode"></SIdentify>
        </div>
      </el-form-item>

<script>
  import SIdentify from "./identify";
  export default {
    name: 'Login',
    data() {
      const sidentify = (rule, value, callback) => {
        let newVal = value.toLowerCase()
        let identifyStr = this.identifyCode.toLowerCase()
        if (newVal === '') {
          callback(new Error('请输入验证码'))
        } else if (newVal !== identifyStr) {
          callback(new Error('验证码错误'))
        } else {
          callback()
        }
      };
      return {
        identifyCodes: '1234567890ABCDEFGHIGKLMNoPQRSTUVWXYZ',//定义随机数范围
        identifyCode: '', //验证码
        loginForm: {
          sidentify: '',
        },
        rules: {
          sidentify: [{ required: true,  validator: sidentify, trigger: 'blur' }]
        },
      };
    },
    components: {
      SIdentify: SIdentify
    },
    mounted() {
      this.identifyCode = "";
      this.makeCode(this.identifyCodes, 4);
    },
    methods: {
      // 生成随机数
      randomNum(min, max) {
            return Math.floor(Math.random() * (max - min) + min)
        },
      // 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)]
        }
      },
      // 切换验证码
      refreshCode() {
        this.identifyCode = ''
        this.makeCode(this.identifyCodes, 4)
      }
    }
  }
</script>