Vue implements graphic verification code

<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: 18
      },
      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: 111
      },
      contentHeight: {
        type: Number,
        default: 38
      }
    },
    methods: {
      // Generate a random number randomNum(min, max) {
        return Math.floor(Math.random() * (max - min) + min)
      },
      // Generate a random color 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'
        // Draw the background ctx.fillStyle = this.randomColor(this.backgroundColorMin, this.backgroundColorMax)
        ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
        // Draw text for (let i = 0; i < this.identifyCode.length; i++) {
          this.drawText(ctx, this.identifyCode[i], i)
        }
        // this.drawLine(ctx) // Draw interference line // this.drawDot(ctx) // Draw interference point},
      // Draw text 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(-30, 30) // Character rotation angle (preferably no more than 45 degrees)
        // Modify the coordinate origin and rotation angle ctx.translate(x, y)
        ctx.rotate(deg * Math.PI / 180)
        ctx.fillText(txt, 0, 0)
        // Restore the coordinate origin and rotation angle ctx.rotate(-deg * Math.PI / 180)
        ctx.translate(-x, -y)
      },
      drawLine(ctx) {
        // Draw interference lines 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) {
        // Draw interference points 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>

<template>
  <div>
    <div>Verification code test</div>
    <div @click="refreshCode()" class="code" style="cursor:pointer;" title="Click to switch verification code">
      <s-identify :identifyCode="identifyCode"></s-identify>
    </div>
  </div>
</template>

<script>
import { defineComponent } from 'vue';
import sIdentify from "@/common/sIdentify.vue";
// import axios from 'axios'
export default defineComponent({
  name: 'WatermarkTest',
  components: { sIdentify },
  data() {
    return {
      identifyCode: "",
      identifyCodes: ['0','1','2','3','4','5','6','7','8','9','a','b','c','d'], //Add the characters you want according to actual needs}
  },
  mounted() {
    this.refreshCode()
 },
 unmounted() {

 },
  methods: {
    // Generate random number randomNum(min, max) {
      max = max + 1
      return Math.floor(Math.random() * (max - min) + min);
    },
    // Update verification code refreshCode() {
      this.identifyCode = "";
      this.makeCode(this.identifyCodes, 4);
      console.log('Current verification code:',this.identifyCode);
    },
    // Randomly generate verification code string makeCode(data, len) {
      console.log('data, len:', data, len)
      for (let i = 0; i < len; i++) {
        this.identifyCode += this.identifyCodes[this.randomNum(0, this.identifyCodes.length-1)]
      }
    },
  },
});
</script>