先看效果图
html部分
<body>
<div >
<input type="text" value="" placeholder="请输入验证码" id="text" class="input-val"/>
<canvas id="canvas" width="106" height="43"></canvas>
</div>
</body>
css部分
<style type="text/css">
body{
margin-top: 12.5rem;
margin-left: 200px;
text-align: center;
}
div{
width: 300px;
height: 200px;
}
input{
width: 110px;
height: 40px;
border-color: skyblue;
border-width: 1.5px;
border-radius: 30px;
border-style: solid;
float: left;
padding-left: 20px;
}
canvas{
border: 1px solid #000000;
}
</style>
重点：js部分
先引用jquery
<script type="text/javascript" src="jquery-3.2.1.min.js"></script>
然后
<script type="text/javascript">
//鼠标事件，我这里是鼠标移开进行验证判断
$(function() {
var show_num = [];
draw(show_num);
$("#canvas").on('click', function() {
draw(show_num);
})
$("#text").mouseout(function(){
var val = $(".input-val").val().toLowerCase();
var num = show_num.join("");
if (val == num) {
$('.btn').attr("disabled", false);
} else {
alert('验证码错误！请重新输入！');
$(".input-val").val('');
draw(show_num);
}
})
})
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,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 <= 3; i++) {
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
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();
}
}
function randomColor() { //得到随机的颜色值
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>
下面附上demo源码：
https://download.csdn.net/download/xiao_xiao_b/11247722