1.打开官网https://packagist.org/
2.输入验证码单词captcha，查看项目列表，并选择喜欢的，比如选择第一个
3.用composer导入到项目中，速度慢先开启中国镜像
composer config -g repo.packagist composer https://packagist.phpcomposer.com4.复制该项目的composer指令
composer require gregwar/captcha
5.此时在项目的vendor下可以看到
6.在控制器Login.php的开的头加入
use Gregwar\Captcha\CaptchaBuilder;7.在控制器Login.php书写验证码方法
<?php
namespace app\index\controller;
use think\Controller;
use Gregwar\Captcha\CaptchaBuilder;
class Login extends Controller
{
public function login()
{
header('Content-type: image/jpeg');
$builder = new CaptchaBuilder();
$builder->build($width = 100, $height = 40, $font = null);
//获取验证码的内容
$phrase = $builder->getPhrase();
//把内容存入session
Session('milkcaptcha',$phrase);
//生成图片
header('Cache-Control: no-cache, must-revalidate');
header('Content-Type: image/jpeg');
$builder->save('out.jpg');
return $this->fetch('login/login');
}
}
注意：加上exit(0) 并且exit(0)前面不能有任何输出
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=<device-width>, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<input type="text" name="captcha" class="form-control" style="width:300px;">
<a onclick="javascript:re_captcha();"><img src="../../images/out.jpg" alt="验证码" title="刷新图片" width="100" height="40" id="c2c98f0de5a04167a9e427d883690ff6" border="0"></a>
</body>
</html>
<script>
function re_captcha() {
$url="";
document.getElementById('c2c98f0de5a04167a9e427d883690ff6').src=$url;
}
</script>
解析：
保存验证码图片到public下
<?php
$builder->save('out.jpg');
或者直接输出图片到网页：
<?php
header('Content-type: image/jpeg');
$builder->output();
或者生成内联图片
<img src="<?php echo $builder->inline(); ?>"/>
验证验证码是否正确：
public function verify()
{
$request = Request::instance();
$builder = new CaptchaBuilder();
$userInput = $request->post('captcha');
dump($userInput);
if($builder->testPhrase($userInput)){
return '正确';
}else{
return '错误';
}
exit;
}