<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>

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

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

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

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)]
    }
  },
}