<div class="form-group" style="display: flex;">
     <div>
      <span>验证码：</span>
      <input type="text" id="code" v-model="code" class="code" placeholder="请输入您的验证码" />
     </div>
     <div class="login-code" @click="refreshCode">
   <!--验证码组件-->
   <s-identify :identifyCode="identifyCode"></s-identify>
   </div>
    </div>

/*验证码样式*/
.code{
 width:124px;
 height:31px;
 border:1px solid rgba(186,186,186,1);
}
.login-code{
  cursor: pointer;
}

import SIdentify from '../components/sidentify'

components: { SIdentify },
data () {
 return {
  identifyCodes: "1234567890",
  identifyCode: "",
  code:"",//text框输入的验证码
 }
}, 

mounted(){
  this.identifyCode = "";
  this.makeCode(this.identifyCodes, 4);
 },

//验证码
randomNum(min, max) {
 return Math.floor(Math.random() * (max - min) + min);
},
  
refreshCode() {
 this.identifyCode = "";
 this.makeCode(this.identifyCodes, 4);
},
makeCode(o, l) {
 for (let i = 0; i < l; i++) {
  this.identifyCode += this.identifyCodes[
   this.randomNum(0, this.identifyCodes.length)
  ];
 }
 console.log(this.identifyCode);
},

<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: 25
  },
  fontSizeMax: {
   type: Number,
   default: 30
  },
  backgroundColorMin: {
   type: Number,
   default: 255
  },
  backgroundColorMax: {
   type: Number,
   default: 255
  },
  colorMin: {
   type: Number,
   default: 0
  },
  colorMax: {
   type: Number,
   default: 160
  },
  lineColorMin: {
   type: Number,
   default: 100
  },
  lineColorMax: {
   type: Number,
   default: 255
  },
  dotColorMin: {
   type: Number,
   default: 0
  },
  dotColorMax: {
   type: Number,
   default: 255
  },
  contentWidth: {
   type: Number,
   default: 112
  },
  contentHeight: {
   type: Number,
   default: 31
  }
 },
 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 < 5; 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 < 80; 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>
.s-canvas {
 height: 38px;
}
.s-canvas canvas{
 margin-top: 1px;
 margin-left: 8px;
}
</style>