vue系列---identify(生成圖片驗證碼)插件

identify

這是一個vue的插件，使用canvas來生成圖形驗證碼。

具體參數如下： 

identify.vue組件（主要用於定義參數和方法）

<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: 16
      },
      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: 112
      },
      contentHeight: {
        type: Number,
        default: 38
      }
    },
    methods: {
      // 生成一個隨機數
      randomNum (min, max) {
        return Math.floor(Math.random() * (max - min) + min)
      },
      // 生成一個隨機的顏色
      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'
        // 繪制背景
        ctx.fillStyle = this.randomColor(this.backgroundColorMin, this.backgroundColorMax)
        ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
        // 繪制文字
        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)
        // 修改坐標原點和旋轉角度
        ctx.translate(x, y)
        ctx.rotate(deg * Math.PI / 180)
        ctx.fillText(txt, 0, 0)
        // 恢復坐標原點和旋轉角度
        ctx.rotate(-deg * Math.PI / 180)
        ctx.translate(-x, -y)
      },
      drawLine (ctx) {
        // 繪制干擾線
        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) {
        // 繪制干擾點
        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>

login.vue(在頁面進行使用)：

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

<script>
import SIdentify    from '@/components/public/identify/identify'

export default {
  name: "codetest",

　　components: {
　　　　Footer,
　　　　SIdentify
　　},

  data() {
    return {
      identifyCodes: "1234567890",
      identifyCode: ""
    };
  },
  mounted() {
    this.identifyCode = "";
    this.makeCode(this.identifyCodes, 4);
  },
  methods: {
    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);
    }
  }
};
</script>

<style>
.code {
  margin: 400px auto;
  width: 114px;
  height: 40px;
  border: 1px solid red;
}
</style>

注意圖片驗證碼的寬高是由參數 contentWidth 和 contentHeight 決定的，所以更改寬高的時候，直接在聲明的參數中進行更改就可。

測試效果：