前端生成验证码

1.封装组件
2.引用组件-生成随机验证码

封装组件

<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: 35,
    },
    fontSizeMax: {
      type: Number,
      default: 35,
    },
    backgroundColorMin: {
      type: Number,
      default: 255,
    },
    backgroundColorMax: {
      type: Number,
      default: 255,
    },
    colorMin: {
      type: Number,
      default: 0,
    },
    colorMax: {
      type: Number,
      default: 160,
    },
    lineColorMin: {
      type: Number,
      default: 100,
    },
    lineColorMax: {
      type: Number,
      default: 255,
    },
    dotColorMin: {
      type: Number,
      default: 0,
    },
    dotColorMax: {
      type: Number,
      default: 255,
    },
    contentWidth: {
      type: Number,
      default: 137,
    },
    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);
      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) / 160);
      ctx.fillText(txt, 0, 0);
      // 恢复坐标原点和旋转角度
      ctx.rotate((-deg * Math.PI) / 160);
      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>

引用组件

<template>
  <div class="mainBox">
    <div @click="refreshCode" class="codeInfo">
      <!--验证码组件-->
      <s-identify :identifyCode="identifyCode" :contentHeight="55"></s-identify>
    </div>
    <div class="info">验证码为: {{ identifyCode }}</div>
  </div>
</template>

<script>
import SIdentify from "@/components/SIdentify/SIdentify";
export default {
  name: "Login",
  components: { SIdentify },
  data() {
    return {
      identifyCode: "", // 验证码
      identifyCodes: "1234567890AbC", // 验证码资源
    };
  },
  mounted() {
    // 初始化验证码
    this.identifyCode = "";
    this.makeCode(4);
  },
  methods: {
    // 刷新验证码
    refreshCode() {
      this.identifyCode = "";
      this.makeCode(4);
    },
    makeCode(len) {
      for (let i = 0; i < len; i++) {
        let arrList = this.identifyCodes.length - 1;
        let index = Math.floor(Math.random() * arrList);
        this.identifyCode += this.identifyCodes[index];
      }
    },
  },
};
</script>
<style>
.mainBox {
  margin: 20px;
  width: 200px;
  font-size: 24px;
}
.codeInfo {
  border: 1px solid #333;
  padding: 10px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #ccc;
}
</style>