React tsx生成随机验证码

import * as React from "react";

const size = 4;
const verifycode = {
    width: "32%",
    height: "32px",
    marginLeft: "5%",
    display:"inline-block",
    position:"absolute" as "absolute",
    top:"0",
    right:"0",
}
export default class InputVerify extends React.Component<any, any> {
    constructor(props) {
        super(props);
        this.state = {
            options: {
                id: "verifycode", //容器Id
                canvasId: "verifyCanvas", //canvas的ID
                width: "150", //默认canvas宽度
                height: "47", //默认canvas高度
                type: "blend", //图形验证码默认类型blend:数字字母混合类型、number:纯数字、letter:纯字母
                code: "",
                numArr: "0,1,2,3,4,5,6,7,8,9".split(","),
                letterArr: this.getAllLetter(),
            }
        }

    }

    componentDidMount() {
        const self = this;
        setTimeout(() => {
            self._init();
            self.refresh();
        }, 100)
        this.props.onRef(this);// 调用父组件传入的函数，把自身赋给父组件
    }

    _init() {
        let con = document.getElementById(this.state.options.id);
        let canvas = document.createElement("canvas");
        this.state.options.width = con.offsetWidth > 0 ? con.offsetWidth : "150";
        this.state.options.height = con.offsetHeight > 0 ? con.offsetHeight : "47";
        canvas.id = this.state.options.canvasId;
        canvas.width = this.state.options.width;
        canvas.height = this.state.options.height;
        canvas.style.cursor = "pointer";
        canvas.innerHTML = "您的浏览器版本不支持canvas";
        con.appendChild(canvas);
        let parent = this;
        canvas.onclick = function () {
            parent.refresh();
        }
    }

    refresh() {
        this.state.options.code = "";
        let canvas : any = document.getElementById(this.state.options.canvasId);
        let ctx = null;
        if (canvas.getContext) {
            ctx = canvas.getContext('2d');
        } else {
            return;
        }
        ctx.clearRect(0, 0, this.state.options.width, this.state.options.height);
        ctx.textBaseline = "middle";

        ctx.fillStyle = this.randomColor(180, 240);
        ctx.fillStyle = "rgba(0,0,0,0)";//背景色
        ctx.fillRect(0, 0, this.state.options.width, this.state.options.height);

        if (this.state.options.type == "blend") { //判断验证码类型
            var txtArr = this.state.options.numArr.concat(this.state.options.letterArr);
        } else if (this.state.options.type == "number") {
            var txtArr = this.state.options.numArr;
        } else {
            var txtArr = this.state.options.letterArr;
        }

        for (var i = 1; i <= size; i++) {
            var txt = txtArr[this.randomNum(0, txtArr.length)];
            this.state.options.code += txt;
            ctx.font = this.randomNum(this.state.options.height / 2, this.state.options.height) + 'px SimHei'; //随机生成字体大小
            ctx.fillStyle = this.randomColor(50, 160); //随机生成字体颜色       
            // ctx.fillStyle = "rgb(46, 137, 255)";//固定字体颜色
            ctx.shadowOffsetX = this.randomNum(-3, 3);
            ctx.shadowOffsetY = this.randomNum(-3, 3);
            ctx.shadowBlur = this.randomNum(-3, 3);
            ctx.shadowColor = "rgba(0, 0, 0, 0.3)";
            var x = this.state.options.width / (size + 1) * i;
            var y = this.state.options.height / 2;
            var deg = this.randomNum(-30, 30);
            /**设置旋转角度和坐标原点**/
            ctx.translate(x, y);
            ctx.rotate(deg * Math.PI / 180);
            ctx.fillText(txt, 0, 0);
            /**恢复旋转角度和坐标原点**/
            ctx.rotate(-deg * Math.PI / 180);
            ctx.translate(-x, -y);
        }
        /**绘制干扰线**/
        for (var i = 0; i < 4; i++) {
            ctx.strokeStyle = this.randomColor(40, 180);
            ctx.beginPath();
            ctx.moveTo(this.randomNum(0, this.state.options.width), this.randomNum(0, this.state.options.height));
            ctx.lineTo(this.randomNum(0, this.state.options.width), this.randomNum(0, this.state.options.height));
            ctx.stroke();
        }
    }

    validate(code) {
        var code = code.toLowerCase();
        var v_code = this.state.options.code.toLowerCase();
        if (code == v_code) {
            return true;
        } else {
            this.refresh();
            return false;
        }
    }
    /**生成字母数组**/
    getAllLetter() {
        var letterStr = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
        return letterStr.split(",");
    }
    /**生成一个随机数**/
    randomNum(min, max) {
        return Math.floor(Math.random() * (max - min) + min);
    }
    /**生成一个随机色**/
    randomColor(min, max) {
        var r = this.randomNum(min, max);
        var g = this.randomNum(min, max);
        var b = this.randomNum(min, max);
        return "rgb(" + r + "," + g + "," + b + ")";
    }

    render() {
        return (
            <div id="verifycode" style={verifycode}></div>
        )
    }
}

import InputVerify from "../InputVerify"

export default ($Child: any = {}) => {
 //Form提交的方法
 const onFinish = (values: any) => {
        if (values.vcode) {
            console.log($Child.validate(values.vcode))//调用子组件的方法验证
        }
    };
    
 const onFinishFailed = (errorInfo: any) => {
        console.log('Failed:', errorInfo);
    };
 
 return (
  <Form
            {...layout}
            name="basic"
            onFinish={onFinish}
            onFinishFailed={onFinishFailed}
        >
         <Form.Item name="vcode" rules={[{ required: true, message: '请输入验证码' }]}>
               <Input size="large" className="security-code" placeholder="请输入验证码" />
            </Form.Item>
   {/* 这里通过onRef来父组件调用子组件的方法 *