package dependencies

"dependencies": {
  "vue": "^2.6.10",
  ...
}

验证码组件

./Identify.vue

<template>
  <div class="s-canvas">
    <canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas>
  </div>
</template>
<script>
export default {
  name: "SIdentify",
  props: {
    // 默认注册码
    identifyCode: {
      type: String,
      default: "1234"
    },
    // 字体最小值
    fontSizeMin: {
      type: Number,
      default: 25
    },
    // 字体最大值
    fontSizeMax: {
      type: Number,
      default: 35
    },
    // 验证码图片背景色最小值
    backgroundColorMin: {
      type: Number,
      default: 200
    },
    // 验证码图片背景色最大值
    backgroundColorMax: {
      type: Number,
      default: 220
    },
    // 背景干扰点最小值
    dotColorMin: {
      type: Number,
      default: 60
    },
    // 背景干扰点最大值
    dotColorMax: {
      type: Number,
      default: 120
    },
    // 容器宽度
    contentWidth: {
      type: Number,
      default: 116
    },
    // 容器高度
    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(50, 160) // 随机生成字体颜色
      ctx.font =
        this.randomNum(this.fontSizeMin, this.fontSizeMax) + "px SimHei" // 随机生成字体大小
      let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1))
      let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5)
      var deg = this.randomNum(-30, 30)
      // 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 < 4; i++) {
        ctx.strokeStyle = this.randomColor(100, 200)
        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>
 
<style scoped>

登录引用

这里使用简化后的demo，实际生产环境可根据业务需要修改 ./SignIn.vue

<template>
  <form>
    <input placeholder='username'/>
    <input placeholder='password'/>
    <input placeholder='captcha'/>
    <Identify :identifyCode='identifyCode' :contentWidth='240' />
    <button @click='changeCode'>Sign in</button>
  </form>
</template>

<script>
import Identify from './Identify'
export default {
  name: 'sign-in',
  components: { Identify },
  data() {
    return {
      identifyCode: '1234', // 验证码初始值
      identifyCodes: '1234567890' // 验证码的随机取值范围
    }
  },
  mounted() {
    changeCode()
  },
  methods: {
    /**
     * 点击验证码刷新验证码
     */
    changeCode() {
      this.identifyCode = ''
      this.makeCode(this.identifyCodes, 4)
    },

    /**
    * 生成一个随机整数  randomNum(0, 10) 0 到 10 的随机整数， 包含 0 和 10
    * @param {Number} min 
    * @param {Number} max 
    */
    randomNum(min, max) {
      max = max + 1
      return Math.floor(Math.random() * (max - min) + min)
    },
    
    /**
    * 随机生成验证码字符串
    * @param {String} data 随机字符池
    * @param {Number} len 字符长度
    */
    makeCode(data, len) {
      for (let i = 0; i < len; i++) {
        this.identifyCode += data[this.randomNum(0, data.length - 1)]
      }
    },
  }
}
</script>