- A+
所属分类:CSS|Html
首先上运行效果图:
下面是代码:
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,minimum-scale=1,user-scalable=no">
- <title>生成图片验证码</title>
- <script src="https://cdn.bootcss.com/jquery/1.12.3/jquery.min.js"></script>
- <style>
- #verify {
- height: 34px;
- vertical-align: top;
- font-size: 16px;
- }
- #code_img {
- width: 100px;
- height: 40px;
- cursor: pointer;
- vertical-align: top;
- }
- </style>
- </head>
- <body>
- 点击图片重新生成验证码
- <p>
- <input type="text" class="topAlign" id="verify" name="verify" required>
- <canvas width="100" height="40" id="verifyCanvas"></canvas>
- <img id="code_img">
- </p>
- <button id="submit" type="submit">提交</button>
- </body>
- <script>
- var nums = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0", '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'
- ];
- var colors = []
- drawCode();
- // 绘制验证码
- function drawCode() {
- var canvas = document.getElementById("verifyCanvas"); //获取HTML端画布
- var context = canvas.getContext("2d"); //获取画布2D上下文
- context.fillStyle = "cornflowerblue"; //画布填充色
- context.fillRect(0, 0, canvas.width, canvas.height);
- // 创建渐变
- var gradient = context.createLinearGradient(0, 0, canvas.width, 0);
- gradient.addColorStop("0", "magenta");
- gradient.addColorStop("0.5", "blue");
- gradient.addColorStop("1.0", "red");
- //清空画布
- context.fillStyle = gradient; //设置字体颜色
- context.font = "25px Arial"; //设置字体
- var rand = new Array();
- var x = new Array();
- var y = new Array();
- for (var i = 0; i < 4; i++) {
- rand[i] = nums[Math.floor(Math.random() * nums.length)]
- x[i] = i * 16 + 10;
- y[i] = Math.random() * 20 + 20;
- context.fillText(rand[i], x[i], y[i]);
- }
- // console.log(rand);
- //画3条随机线
- for (var i = 0; i < 3; i++) {
- drawline(canvas, context);
- }
- // 画30个随机点
- for (var i = 0; i < 30; i++) {
- drawDot(canvas, context);
- }
- convertCanvasToImage(canvas)
- // 点击提交进行验证
- $("#submit").click((e) => {
- var newRand=rand.join('').toUpperCase();
- //下面就是判断是否== 的代码,无需解释
- var oValue = $('#verify').val().toUpperCase();
- console.log(oValue)
- if (oValue == 0) {
- console.log('请输入验证码');
- } else if (oValue != newRand) {
- console.log('验证码不正确,请重新输入');
- oValue = '';
- } else {
- window.open('http://www.baidu.com', '_self');
- }
- })
- }
- // 随机线
- function drawline(canvas, context) {
- context.moveTo(Math.floor(Math.random() * canvas.width), Math.floor(Math.random() * canvas.height)); //随机线的起点x坐标是画布x坐标0位置,y坐标是画布高度的随机数
- context.lineTo(Math.floor(Math.random() * canvas.width), Math.floor(Math.random() * canvas.height)); //随机线的终点x坐标是画布宽度,y坐标是画布高度的随机数
- context.lineWidth = 0.5; //随机线宽
- context.strokeStyle = 'rgba(50,50,50,0.3)'; //随机线描边属性
- context.stroke(); //描边,即起点描到终点
- }
- // 随机点(所谓画点其实就是画1px像素的线,方法不再赘述)
- function drawDot(canvas, context) {
- var px = Math.floor(Math.random() * canvas.width);
- var py = Math.floor(Math.random() * canvas.height);
- context.moveTo(px, py);
- context.lineTo(px + 1, py + 1);
- context.lineWidth = 0.2;
- context.stroke();
- }
- // 绘制图片
- function convertCanvasToImage(canvas) {
- document.getElementById("verifyCanvas").style.display = "none";
- var image = document.getElementById("code_img");
- image.src = canvas.toDataURL("image/png");
- return image;
- }
- // 点击图片刷新
- document.getElementById('code_img').onclick = function () {
- $('#verifyCanvas').remove();
- $('#verify').after('<canvas width="100" height="40" id="verifyCanvas"></canvas>')
- drawCode();
- }
- </script>
- </html>
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