前端验证码生成器插件

此验证码生成器可以允许在前端直接生成验证码和从后端获取后台生成的验证码两种方式

前端JS插件

var getGVerify = function (id) {
    function GVerify(options) { //创建一个图形验证码对象，接收options对象为参数
        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
            code: ""
        }

        if(Object.prototype.toString.call(options) == "[object Object]"){//判断传入参数类型
            for(var 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.numArr = getAllNumber();
        this.options.letterArr = getAllLetter();

        this._init();
        this.refresh();
    }

    GVerify.prototype = {
        /**版本号**/
        version: '2.1.0',

        /**初始化方法**/
        _init: function() {
            var con = document.getElementById(this.options.id);
            var canvas = document.createElement("canvas");
            canvas.id = this.options.canvasId;
            canvas.width = this.options.width;
            canvas.height = this.options.height;
            canvas.title = '点击更换验证码';
            canvas.style.cursor = "pointer";
            canvas.innerHTML = "您的浏览器版本不支持canvas";
            con.appendChild(canvas);
            var parent = this;
            canvas.onclick = function(){
              parent.refresh();
            }
        },

        /**生成验证码**/
        refresh: function() {
            this.options.code = '';
            var canvas = document.getElementById(this.options.canvasId);
            if(canvas.getContext) {
                var ctx = canvas.getContext('2d');
            }

            ctx.textBaseline = "middle";
            ctx.fillStyle = randomColor(180, 240);
            ctx.fillRect(0, 0, this.options.width, this.options.height);

            /*验证码长度为4*/
            var txtArr = new Array(4);
            /*方法一：后台获取验证码*/
            /*var xhr = new XMLHttpRequest();
            xhr.onreadystatechange = function(){
                if(xhr.readyState == 4){
                    txtArr = xhr.responseText.split(","); //返回如: a,b,c,d
                }
            }
            xhr.open('get', '/signin/getVerifyCode', false); //同步

            /*方法二：前端直接生成验证码*/
            var codeLetter = getAllNumber().concat(getAllLetter());
            for(var i = 0; i < 4; i++){
                txtArr[i] = codeLetter[Math.floor(Math.random() * codeLetter.length)];
            }
            for(var i = 1; i <= 4; i++) {
                //选取
                var txt = txtArr[i-1];
                this.options.code += txt;

                //设置字体大小
                ctx.font = '30px SimHei';
                //ctx.font = randomNum(this.options.height/2, this.options.height) + 'px SimHei';

                //随机生成字体颜色
                ctx.fillStyle = randomColor(50, 160);
                ctx.shadowBlur = randomNum(-3, 3);
                ctx.shadowColor = "rgba(0, 0, 0, 0.3)";

                /**设置旋转角度和坐标原点**/
                var x = this.options.width / 5 * i;
                var y = this.options.height / 2;
                var deg = randomNum(-30, 30);
                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 = randomColor(40, 180);
                ctx.beginPath();
                ctx.moveTo(randomNum(0, this.options.width/2),
                           randomNum(0, this.options.height/2));
                ctx.lineTo(randomNum(0, this.options.width/2), 
                           randomNum(0, this.options.height));
                ctx.stroke();
            }
            /**绘制干扰点**/
            for(var i = 0; i < this.options.width/4; i++) {
                ctx.fillStyle = randomColor(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: function(code){
            var verifyCode = code.toLowerCase();
            var v_code = this.options.code.toLowerCase();
            return verifyCode == v_code;
        }
    }
    /**生成数字数组**/
    function getAllNumber() {
        return "0,1,2,3,4,5,6,7,8,9".split(",");
    }
    /**生成字母数组**/
    function 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**/
    function randomNum(min, max) {
        return Math.floor(Math.random() * (max - min) + min);
    }
    /**生成一个随机色**/
    function randomColor(min, max) {
        var r = randomNum(min, max);
        var g = randomNum(min, max);
        var b = randomNum(min, max);
        return "rgb(" + r + "," + g + "," + b + ")";
    }

    return new GVerify(id);
}

后台JS(Nodejs、非必须）

function sendVerifyCode(req, res){
    var codeLetter = "0,1,2,3,4,5,6,7,8,9,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".split(",");
    var result = new Array(4);
    for(var i = 0; i < 4; i++){
        result[i] = codeLetter[Math.floor(Math.random() * codeLetter.length)];
    }
    res.send(result.join(","));
}

使用方法

var GVerify = getGVerify({
    id: "verify",
    canvasId: "verifyCanvas",
    width: "100",
    height: "50",
    type: "blend",
    code: ""
});