<%--
  Created by IntelliJ IDEA.
  User: NEUSOFT
  Date: 2019/3/27
  Time: 10:40
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <link rel="shortcut icon" href="http://dsada1.oss-cn-beijing.aliyuncs.com/img/xicon.png" type="image/x-icon">
    <style>
        .input-val {
            width: 200px;
            height: 32px;
            border: 1px solid #ddd;
            box-sizing: border-box;
        }
        #canvas {
            vertical-align: middle;
            box-sizing: border-box;
            border: 1px solid #ddd;
            cursor: pointer;
        }
        .btn {
            display: block;
            margin-top: 20px;
            height: 32px;
            width: 100px;
            font-size: 16px;
            color: #fff;
            background-color: #457adb;
            border: none;
            border-radius: 50px;
        }
    </style>
    <script type="text/javascript" src="bootstrap/js/jquery-3.3.1.min.js" ></script>
    <script>
        $(function(){
            var show_num = [];
            draw(show_num);
            $("#canvas").on('click',function(){
                draw(show_num);
            })
            $(".btn").on('click',
                function(){
                    var val = $(".input-val").val().toLowerCase();
                    var num = show_num.join("");
                    if(val==''){
                        alert('请输入验证码！');
                        return false;
                    }else if(val == num){
                        alert('提交成功！');
                        $(".input-val").val('');
                        return true;
                        // draw(show_num);
                    }else{
                        alert('验证码错误！请重新输入！');
                        draw(show_num);
                        $(".input-val").val('');
                        return false;
                        // draw(show_num);
                    }
                })
        })
        //生成并渲染出验证码图形
        function draw(show_num) {
            var canvas_width=$('#canvas').width();
            var canvas_height=$('#canvas').height();
            var canvas = document.getElementById("canvas");//获取到canvas的对象，演员
            var context = canvas.getContext("2d");//获取到canvas画图的环境，演员表演的舞台
            canvas.width = canvas_width;
            canvas.height = canvas_height;
            var sCode = "a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0";
            var aCode = sCode.split(",");
            var aLength = aCode.length;//获取到数组的长度
            for (var i = 0; i < 4; i++) { //这里的for循环可以控制验证码位数（如果想显示6位数，4改成6即可）
                var j = Math.floor(Math.random() * aLength);//获取到随机的索引值
                // var deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
                var deg = Math.random() - 0.5; //产生一个随机弧度
                var txt = aCode[j];//得到随机的一个内容
                show_num[i] = txt.toLowerCase();
                var x = 10 + i * 20;//文字在canvas上的x坐标
                var y = 20 + Math.random() * 8;//文字在canvas上的y坐标
                context.font = "bold 23px 微软雅黑";
                context.translate(x, y);
                context.rotate(deg);
                context.fillStyle = randomColor();
                context.fillText(txt, 0, 0);
                context.rotate(-deg);
                context.translate(-x, -y);
            }
            for (var i = 0; i <= 5; i++) { //验证码上显示线条
                context.strokeStyle = randomColor();
                context.beginPath();
                context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
                context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
                context.stroke();
            }
            for (var i = 0; i <= 30; i++) { //验证码上显示小点
                context.strokeStyle = randomColor();
                context.beginPath();
                var x = Math.random() * canvas_width;
                var y = Math.random() * canvas_height;
                context.moveTo(x, y);
                context.lineTo(x + 1, y + 1);
                context.stroke();
            }
        }
        //得到随机的颜色值
        function randomColor() {
            var r = Math.floor(Math.random() * 256);
            var g = Math.floor(Math.random() * 256);
            var b = Math.floor(Math.random() * 256);
            return "rgb(" + r + "," + g + "," + b + ")";
        }
    </script>
</head>
<body>
<h2>regist</h2>
<form action="registSuccess.action">
    username:<input type="text" name="username"/><br>
    password:<input type="password" name="password"/><br>
    <input type="text" value="" placeholder="请输入验证码（不区分大小写）" class="input-val"/>
    <canvas id="canvas" width="100" height="30"></canvas>
    <button class="btn" type="submit">regist</button>
<%--username:<input type="text" name="username"/><br>--%>
<%--password:<input type="password" name="password"/><br>--%>
<%--<input type="submit" value="regist">--%>
</form>
</body>
</html>
