JavaScript+html实现前端页面随机二维码验证

分享炫酷的前端页面随机二维码验证,供大家参考,具体内容如下

直接上代码

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

<title>Title</title>

<!--引入jquery的js -->

<script type="text/javascript" src="../jquery/jquery.js"></script>

</head>

<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>

<body>

<div class="code">

<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">提交</button>

</div>

</body>

<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!');

}else if(val == num){

alert('提交成功!');

$(".input-val").val('');

// draw(show_num);

}else{

alert('验证码错误!请重新输入!');

$(".input-val").val('');

// 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>

</html>

效果如下

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

以上是 JavaScript+html实现前端页面随机二维码验证 的全部内容, 来源链接: utcz.com/p/220698.html

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