web-utils-super/createCodeImg.js

前端函数库

const getLetter = require('../string/getAllLetter')
const randomNum = require('../random/randomNum')
const randomColorRGB = require('../random/randomColorRGB')

class GVerify {
  constructor(options, code) {
    //创建一个图形验证码对象，接收options对象为参数
    this.size = code.length; //设置验证码长度
    this.options = {
      //默认options参数值
      id: "", //容器Id
      canvasId: "verifyCanvas", //canvas的ID
      width: "100", //默认canvas宽度
      height: "30", //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: code,
    };
    if (Object.prototype.toString.call(options) == "[object Object]") {
      //判断传入参数类型
      for (let i in options) {
        //根据传入的参数，修改默认参数值
        this.options[i] = options[i];
      }
    } else {
      this.options.id = options;
    }
    this.options.canvasId = this.options.canvasId + '_' + this.options.id
    this.options.numArr = "0,1,2,3,4,5,6,7,8,9".split(",");
    this.options.letterArr = getLetter();

    this._init();
    this.refresh();
  }
  /**初始化方法**/
  _init() {
    let con = document.getElementById(this.options.id);
    let canvas = document.createElement("canvas");
    this.options.width = con.offsetWidth > 0 ? con.offsetWidth : "100";
    this.options.height = con.offsetHeight > 0 ? con.offsetHeight : "30";
    canvas.id = this.options.canvasId;
    canvas.width = this.options.width;
    canvas.height = this.options.height;
    canvas.style.cursor = "pointer";
    canvas.innerHTML = "您的浏览器版本不支持canvas";
    con.appendChild(canvas);
  }
  /**生成验证码**/
  refresh(code = "") {
    this.options.code = code ? code : this.options.code;
    this.size = this.options.code.length;
    let canvas = document.getElementById(this.options.canvasId);
    let ctx = null;
    if (canvas.getContext) {
      ctx = canvas.getContext("2d");
    } else {
      return;
    }

    ctx.textBaseline = "middle";

    ctx.fillStyle = randomColorRGB(180, 240);
    ctx.fillRect(0, 0, this.options.width, this.options.height);
    for (let i = 0; i < this.size; i++) {
      let txt = this.options.code[i];
      // this.options.code += txt;
      ctx.font =
        randomNum(this.options.height / 2, this.options.height) + "px SimHei"; //随机生成字体大小
      ctx.fillStyle = randomColorRGB(50, 160); //随机生成字体颜色
      ctx.shadowOffsetX = randomNum(-3, 3);
      ctx.shadowOffsetY = randomNum(-3, 3);
      ctx.shadowBlur = randomNum(-3, 3);
      ctx.shadowColor = "rgba(0, 0, 0, 0.3)";
      let x = (this.options.width / (this.size + 1)) * i;
      let y = this.options.height / 2;
      let deg = 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 (let i = 0; i < this.size - 1; i++) {
      ctx.strokeStyle = randomColorRGB(40, 180);
      ctx.beginPath();
      ctx.moveTo(
        randomNum(0, this.options.width),
        randomNum(0, this.options.height)
      );
      ctx.lineTo(
        randomNum(0, this.options.width),
        randomNum(0, this.options.height)
      );
      ctx.stroke();
    }
    /**绘制干扰点**/
    for (let i = 0; i < this.options.width / this.size; i++) {
      ctx.fillStyle = randomColorRGB(0, 255);
      ctx.beginPath();
      ctx.arc(
        randomNum(0, this.options.width),
        randomNum(0, this.options.height),
        1,
        0,
        2 * Math.PI
      );
      ctx.fill();
    }
  }
  /**验证验证码**/
  validate(code) {
    code = code.toLowerCase();
    let v_code = this.options.code.toLowerCase();
    if (code == v_code) {
      return true;
    } else {
      this.refresh();
      return false;
    }
  }
}

module.exports = GVerify;