用jquery写验证码怎么写
时间: 2023-07-05 16:05:38 浏览: 49
可以使用以下代码来生成一个简单的验证码:
HTML代码:
```html
<label for="captcha">验证码:</label>
<input type="text" id="captcha" name="captcha">
<button id="refresh-captcha">刷新</button>
<canvas id="captcha-canvas" width="100" height="40"></canvas>
```
JavaScript代码:
```javascript
$(document).ready(function(){
var canvas = document.getElementById('captcha-canvas');
var ctx = canvas.getContext('2d');
var captcha = '';
var possibleChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
function generateCaptcha() {
captcha = '';
for (i = 0; i < 6; i++) {
captcha += possibleChars.charAt(Math.floor(Math.random() * possibleChars.length));
}
return captcha;
}
function drawCaptcha() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.font = 'bold 20px Arial';
ctx.fillText(captcha, 10, 30);
}
$('#refresh-captcha').click(function() {
captcha = generateCaptcha();
drawCaptcha();
});
captcha = generateCaptcha();
drawCaptcha();
});
```
这段代码使用了 canvas 来绘制验证码,每次点击刷新按钮时会重新生成一个新的验证码并在 canvas 中绘制出来。同时,也会在输入框中更新验证码的值。