步骤1 创建一个名为identify.vue的子组件

<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: 35
},
// 字体最大值
fontSizeMax: {
    type: Number,
    default: 35
},
// 背景颜色色值最小值
backgroundColorMin: {
    type: Number,
    default: 180
},
// 背景颜色色值最大值
backgroundColorMax: {
    type: Number,
    default: 240
},
// 字体颜色色值最小值
colorMin: {
    type: Number,
    default: 50
},
// 字体颜色色值最大值
colorMax: {
    type: Number,
    default: 160
},
// 干扰线颜色色值最小值
lineColorMin: {
    type: Number,
    default: 100
},
// 干扰线颜色色值最大值
lineColorMax: {
    type: Number,
    default: 200
},
// 干扰点颜色色值最小值
dotColorMin: {
    type: Number,
    default: 0
},
// 干扰点颜色色值最大值
dotColorMax: {
    type: Number,
    default: 255
},
// 画布宽度
contentWidth: {
    type: Number,
    default: 120
},
// 画布高度
contentHeight: {
    type: Number,
    default: 40
}
 },
 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) {
 // 随机生产字体颜色
  ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax)
  // 随机生成字体大小
  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>

步骤2 在子组件中进行注册和引用 

<script>
    import SIdentify from "./common/sIdentify.vue";
    export default {
        components: { SIdentify },
    }
</script>

步骤3 在主页面中使用子组件
1、template中：

<template>
  <div   @click="refreshCode">
    <s-identify :identifyCode="identifyCode"></s-identify>
  </div>
</template>

2、 data中：

data() {
     return {
         identifyCode: "",
         identifyCodes: "",
     }
},

3、methods中：

methods: {
    // 生成随机数
    randomNum(min, max) {
        max = max + 1
        return Math.floor(Math.random() * (max - min) + min);
    },
    // 更新验证码
    refreshCode() {
        this.identifyCode = "";
        this.makeCode(this.identifyCodes, 4);
        console.log('当前验证码==',this.identifyCode);
    },
    // 随机生成验证码字符串
    makeCode(data, len) {
        for (let i = 0; i < len; i++) {
            this.identifyCode += this.identifyCodes[this.randomNum(0, this.identifyCodes)]
        }
    },
}

链接: https://fly63.com/article/detial/10027