Vue實現隨機驗證碼功能

步驟1 建立一個名爲identify.vue的子組件

<template>
 <div class="s-canvas">
 <canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas>
 </div>
</template>
<script>
export default {
 name: 'SIdentify',
 props: {
 // 默認註冊碼
identifyCode: {
    type: String,
    default: "1234"
},
// 字體最小值
fontSizeMin: {
    type: Number,
    default: 35
},
// 字體最大值
fontSizeMax: {
    type: Number,
    default: 35
},
// 背景顏色色值最小值
backgroundColorMin: {
    type: Number,
    default: 180
},
// 背景顏色色值最大值
backgroundColorMax: {
    type: Number,
    default: 240
},
// 字體顏色色值最小值
colorMin: {
    type: Number,
    default: 50
},
// 字體顏色色值最大值
colorMax: {
    type: Number,
    default: 160
},
// 干擾線顏色色值最小值
lineColorMin: {
    type: Number,
    default: 100
},
// 干擾線顏色色值最大值
lineColorMax: {
    type: Number,
    default: 200
},
// 干擾點顏色色值最小值
dotColorMin: {
    type: Number,
    default: 0
},
// 干擾點顏色色值最大值
dotColorMax: {
    type: Number,
    default: 255
},
// 畫布寬度
contentWidth: {
    type: Number,
    default: 120
},
// 畫布高度
contentHeight: {
    type: Number,
    default: 40
}
 },
 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'
  // 繪製背景
  ctx.fillStyle = this.randomColor(this.backgroundColorMin, this.backgroundColorMax)
  ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
  // 繪製文字
  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) {
 // 隨機生產字體顏色
  ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax)
  // 隨機生成字體大小
  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)
  // 修改座標原點和旋轉角度
  ctx.translate(x, y)
  ctx.rotate(deg * Math.PI / 180)
  ctx.fillText(txt, 0, 0)
  // 恢復座標原點和旋轉角度
  ctx.rotate(-deg * Math.PI / 180)
  ctx.translate(-x, -y)
 },
 drawLine(ctx) {
  // 繪製干擾線
  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) {
  // 繪製干擾點
  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>

步驟2 在子組件中進行註冊和引用

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

步驟3 在主頁面中使用子組件
一、template中：

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

二、 data中：

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

三、methods中：

 methods: {
    // 生成隨機數
    randomNum(min, max) {
        max = max + 1
        return Math.floor(Math.random() * (max - min) + min);
    },
    // 更新驗證碼
    refreshCode() {
        this.identifyCode = "";
        this.makeCode(this.identifyCodes, 4);
        console.log('當前驗證碼==',this.identifyCode);
    },
    // 隨機生成驗證碼字符串
    makeCode(data, len) {
        for (let i = 0; i < len; i++) {
            this.identifyCode += this.identifyCodes[this.randomNum(0, this.identifyCodes)]
        }
    },
}

轉載於：https://blog.csdn.net/Serena_tz/article/details/111866600