前端自定义验证码，校验验证码，验证码时效

最近做的项目，不需要后端接口，只需要前端验证，如图

初始页面

获取验证码

验证码的文件，直接复制就行

<template>
    <div class="s-canvas">
      <canvas
        id="s-canvas"
        :width="contentWidth"
        :height="contentHeight"
      ></canvas>
    </div>
  </template>
  <script>
  export default {
    name: "SIdentify",
    props: {
      identifyCode: {
        // 默认注册码
        type: String,
        default: "1234",
      },
      fontSizeMin: {
        // 字体最小值
        type: Number,
        default: 25,
      },
      fontSizeMax: {
        // 字体最大值
        type: Number,
        default: 35,
      },
      backgroundColorMin: {
        // 验证码图片背景色最小值
        type: Number,
        default: 200,
      },
      backgroundColorMax: {
        // 验证码图片背景色最大值
        type: Number,
        default: 220,
      },
      dotColorMin: {
        // 背景干扰点最小值
        type: Number,
        default: 60,
      },
      dotColorMax: {
        // 背景干扰点最大值
        type: Number,
        default: 120,
      },
      contentWidth: {
        // 容器宽度
        type: Number,
        default: 90,
      },
      contentHeight: {
        // 容器高度
        type: Number,
        default: 38,
      },
    },
    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 + ")";
      },
      //画图
      drawPic() {
        let canvas = document.getElementById("s-canvas");
        //创建一个2D对象作为上下文。
        let ctx = canvas.getContext("2d");
        ctx.textBaseline = "bottom";
        // 绘制背景
        ctx.fillStyle = "#e6ecfd";
        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);
      },
      //在画布上显示数据
      drawText(ctx, txt, i) {
        ctx.fillStyle = this.randomColor(50, 160); // 随机生成字体颜色
        ctx.font =
          this.randomNum(this.fontSizeMin, this.fontSizeMax) + "px SimHei"; // 随机生成字体大小
        let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1));
        let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5);
        var 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) / 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);
      },
  
      // 绘制干扰线
      drawLine(ctx) {
        for (let i = 0; i < 4; i++) {
          ctx.strokeStyle = this.randomColor(100, 200);
          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();
        }
      },
  
      // 绘制干扰点
      drawDot(ctx) {
        for (let i = 0; i < 30; 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>
  
  

登录页面，运用验证码

<div style="position: relative;margin: 20px 0;">
   <el-input style="width: 100px;margin-right: 10px;" v-model="code" placeholder="验证码"> 
   </el-input>
   //组件       
   <dentify v-if="identifyCode" :identifyCode="identifyCode" style="width: 100px;height: 4 
     0px;display: inline-block;position: absolute;top: 0px;"></dentify>
   <el-button v-if="identifyCode" @click="refreshCode" style="margin-left: 100px;color: 
    #c4c4c4;">换一换</el-button>
   <el-button v-else  @click="refreshCode" style="color: #c4c4c4;">获取验证码</el-button>               
</div>
<el-button @click="Submit" class="buton">登录 </el-button>

import dentify from "@/components/dentify.vue";
export default {
  components: {
    dentify,
  },
  data() {
    return {
      code:'',
      identifyCodes: "1234567890abcdefjhijklinopqrsduvwxyz", //随机串内容,从这里随机抽几个显示验证码
      identifyCode: "", //验证码图片内容
      timer: null, //设置计时器
      count:'',
    };
  },
  methods: {
//判断验证码并提交
    async Submit() {
      console.log(this.count,'count')
      if(this.identifyCode ==''){
        this.$message({
          message: '获取验证码',
          type: 'warning'
        });
      }else if(this.count == 0){
        this.$message.error("验证码失效");
      }else if(this.code == ''){
        this.$message.error("验证码不能为空");
      }else if(this.identifyCode == this.code){
        await GET_LOGIN(this.form).then((res) => {
        console.log(res, "ress");
        if (res.code == 200) {
          this.$message({
            message: "登陆成功",
            type: "success",
          });

        } else {
          this.$message.error(res.msg);
        }
      });
      }else{
        this.$message.error("验证码错误");
      }
     
    },
    // 重置验证码并倒计时
    refreshCode() {
      this.identifyCode = "";
      this.count = ""
      this.makeCode(this.identifyCodes, 4);
      let TIME_COUNT = 60;
      if (!this.timer) {
        this.count = TIME_COUNT;
        this.timer = setInterval(() => {
          if (this.count > 0 && this.count <= TIME_COUNT) { 
            this.count--;
          } else {
            clearInterval(this.timer);
            this.timer = null;
          }
        }, 1000);
      }
    },
    //获取验证码的值
    makeCode(o, l) {
      for (let i = 0; i < l; i++) {
        //通过循环获取字符串内随机几位
        this.identifyCode +=
          this.identifyCodes[this.randomNum(0, this.identifyCodes.length)];
      }
     
    },
    
    //随机数字：用于当角标拿字符串的值
    randomNum(min, max) {
      return Math.floor(Math.random() * (max - min) + min);
    },

   }
 }