源码搜藏网

本文实例为大家分享了vue实现登录时图形验证码的具体代码，供大家参考，具体内容如下

效果图：

点击图案可以切换字符

1.新建 Identify.vue 组件

<template>
 <div>
 <canvas
   id="s-canvas"
   :width="contentWidth"
   :height="contentHeight"></canvas>
 </div>
</template>

<script>
export default {
 name: "identify",
 props: {
  identifyCode: {
   type: String,
   default: ''
  },
  fontSizeMin: {
   type: Number,
   default: 28
  },
  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: 130
  },
  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) {
   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)
   let 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 / 270)
   ctx.fillText(txt, 0, 0)
   // 恢复坐标原点和旋转角度
   ctx.rotate(-deg * Math.PI / 270)
   ctx.translate(-x, -y)
  },
  drawLine (ctx) {
   // 绘制干扰线
   for (let i = 0; i < 2; 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 < 20; 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 lang="scss" scoped>
#s-canvas {
 height: 38px;
}
</style>

2.在父组件 index.vue注册使用

<template>
 <div @click="refreshCode" style="cursor: pointer;">
    <Identify :identifyCode="identifyCode" ></Identify>
  </div>
</template>

<script>
import Identify from '@/components/test/identify'
export default {
 name: "index",
 components:{
 Identify
 },
 data(){
  return {
   identifyCode: '',
   // 验证码规则
   identifyCodes: '123456789ABCDEFGHGKMNPQRSTUVWXYZ',
 }
 },
 methods:{
 // 切换验证码
  refreshCode() {
   this.identifyCode = ''
   this.makeCode(this.identifyCodes, 4)
   console.log(this.identifyCode)
  },
  // 生成随机验证码
  makeCode(o, l) {
   for (let i = 0; i<l; i++) {
    this.identifyCode += this.identifyCodes[
      Math.floor(Math.random() * (this.identifyCodes.length - 0) + 0)
      ]
   }
 },
 mounted() {
   this.refreshCode()
 }
}
</script>

<style scoped>

</style>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持源码搜藏网。