php-一个简单验证码类

The Captcha Class

白朗ssl适用于网站、小程序/APP、API接口等需要进行数据传输应用场景，ssl证书未来市场广阔！成为成都创新互联的ssl证书销售渠道，可以享受市场价格4-6折优惠！如果有意向欢迎电话联系或者加微信：18982081108（备注：SSL证书合作）期待与您的合作！

outputImage();
        }
        
        function check($arr) {
            if (isset($arr) && is_array($arr)) {
                if (isset($arr[$this->sessionvar])) {
                    if ($arr[$this->sessionvar] == $_SESSION[$this->sessionvar]) {
                        return true;
                    }
                }
            }
        }
        
        function randomString($length = 6) {
            $chars = "abcdefghijklmnopqrstuvwxyz0123456789";
            for ($i = 0; $i < $length; $i++) {
                $string .= $chars[mt_rand(0, strlen($chars)-1)];
            }
            return $string;
        }
        
        function outputImage() {
            $this->img = ImageCreate ($this->width, $this->height);
            if ($this->img) {
                header("Content-type: p_w_picpath/png"); 
                
                $bg = ImageColorAllocate($this->img, 255, 255, 255); 
                $txt = ImageColorAllocate($this->img, 0, 0, 0); 
                
                $string = $this->randomString($this->chars);
                
                ImageString($this->img, 31, $this->fontsize, 0, $string, $txt);
                Imagepng($this->img); 
                
                $_SESSION[$this->sessionvar] = $string; 
            }
        }
    }
?>

The class has two main functions, run() and check() – The run function will output an p_w_picpath so make sure the HTML p_w_picpath tag is linked to the file where you use the run() function. Examples below.

Showing the Image

include('captcha.php');
$captcha = new Captcha;
$captcha->run();

If you name that file cp_w_picpath.php you can embed it into forms in the following way:

Checking the code

Wherever your form is submitting to is where you should be checking the code. This can either be in the same file or an external file. The following code will allow you to check the $_POST array and make sure the user has entered the correct code.

include('captcha.php');
$captcha = new Captcha;

if ($captcha->check($_POST)) {
    echo 'Correct Code';
} else {
    echo 'Invalid Code';
}

生成图

新闻标题：php-一个简单验证码类
文章源于：http://cdxtjz.cn/article/ipdjji.html