PHP 验证码生成类(可定制长度和内容)

时间:2022-11-29 09:42:31

===================VerifyTool======================

PHP 验证码生成类(可定制长度和内容)PHP 验证码生成类(可定制长度和内容)
<?php

class VerifyTool
{
    private $fontPath;      //字体路径
    private $verifyStr;     //字符库
    private $verifyLen;     //字符数
    private $verifyCode;    //验证码
    private $verifyImg;     //验证图像

    public function __construct($fontPath)
    {
        $this->fontPath = $fontPath;
        $this->verifyLen = 4;
        $this->verifyStr = '0123456789'
            . 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
            . 'abcdefghijklmnopqrstuvwxyz';
    }

    /**
     * 设置验证码所包含的字符
     * @param $str
     */
    public function setChars($str)
    {
        $this->verifyStr = $str;
    }

    /**
     * 设置验证码字符串长度
     * @param $num
     */
    public function setLength($num)
    {
        $this->verifyLen = $num;
    }

    /**
     * 得到验证码的内容(默认转换为小写)
     * @param bool $tolower
     * @return string
     */
    public function getCode($tolower = true)
    {
        if ($tolower) {
            return strtolower($this->verifyCode);
        } else {
            return $this->verifyCode;
        }
    }

    /**
     * 绘制验证码图像
     * @return $this
     */
    public function drawImage()
    {
        $width = $this->verifyLen * 50;//图片宽度
        $height = 60;//图片高度
        $graylevel = 240;//背景灰度
        $fontsize = 24;//字体大小
        $content = '';//验证码内容
        $image = imagecreatetruecolor($width, $height);
        $bgcolor = imagecolorallocate($image, $graylevel, $graylevel, $graylevel);
        imagefill($image, 0, 0, $bgcolor);
        //绘制随机字符
        for ($i = 0; $i < $this->verifyLen; $i++) {
            $fontcolor = imagecolorallocate($image, rand(120, 220), rand(60, 150), rand(100, 200));
            $fontchar = mb_substr($this->verifyStr, rand(0, mb_strlen($this->verifyStr, 'utf8') - 1), 1, 'utf8');
            $x = ($i * $width / $this->verifyLen) + rand(10, 20);
            $y = $height / 2 + rand(-5, 5) + $fontsize / 2;
            imagettftext($image, $fontsize, rand(-60, 60), $x, $y, $fontcolor, $this->fontPath, $fontchar);
            $content .= $fontchar;
        }
        //绘制随机点
        for ($i = 0; $i < $this->verifyLen * 10; $i++) {
            $pointcolor = imagecolorallocate($image, rand(50, 200), rand(50, 200), rand(50, 200));
            imagefilledellipse($image, rand(0, $width), rand(0, $height), 5, 5, $pointcolor);
        }
        //绘制随机直线
        for ($i = 0; $i < $this->verifyLen; $i++) {
            $linecolor = imagecolorallocatealpha($image, rand(60, 120), rand(80, 160), rand(60, 120), rand(80, 100));
            imageline($image, 0, rand(0, $height - 0), $width, rand(0, $height - 0), $linecolor);
        }
        $this->verifyCode = $content;
        $this->verifyImg = $image;
        return $this;
    }

    /**
     * 显示验证码
     */
    public function show()
    {
        header('content-type: image/png');
        imagepng($this->verifyImg);
        imagedestroy($this->verifyImg);
    }
}
VerifyTool.class.php

==================使用方式====================

创建一个verify_image.php文件:

<?php
//开启SESSION
session_start();
//引入验证码工具
require_once 'VerifyTool.class.php';
//初始化工具(必须传入有效的字体路径)
$verifyTool = new VerifyTool('../res/simhei.ttf');
//绘制图像并显示
$verifyTool->drawImage()->show();
//将验证码信息保存至SESSION
$_SESSION['verify_code'] = $verifyTool->getCode();  

如果直接打开效果如下:

PHP 验证码生成类(可定制长度和内容)

还可以为验证工具设置参数:

$verifyTool = new VerifyTool('../res/simhei.ttf');
//设置验证码字符内容
$verifyTool->setChars('巧学巧用');
//设置验证码长度
$verifyTool->setLength(10);
$verifyTool->drawImage()->show();

设置参数后效果如下:

PHP 验证码生成类(可定制长度和内容)

==================验证方式====================

创建一个 verify_test.php 文件:

<?php
//如果需要使用SESSION,必须在脚本开始处开启SESSION
session_start();
?>
    <!--显示验证码和输入框-->
    <img src="verify_image.php">
    <form action="verify_test.php" method="get">
        <input type="text" name="mycode">
        <input type="submit" value="submit">
    </form>

<?php
if (!empty($_GET['mycode'])) {
    //去除用户输入的多余空格,并将输入转换为小写字母
    $mycode = strtolower(trim($_GET['mycode']));
    //将SESSION保存的验证码信息取出,并进行比较
    if ($mycode == $_SESSION['verify_code']) {
        echo '验证成功,请继续';
    } else {
        echo '验证失败,请重试';
    }
}

这仅仅是测试验证码的小Demo,如果要在其他场景下使用的话,就需要理解其中的原理,做到巧学巧用才行。