PHP 简单面向对象 验证码类（静态实例对象调用）

没事写了一个简单的面向对象验证码类，可以直接使用（替换一下字体路径）

<?php

class authcode
{
    private static $instance = null;     #实例对象
    private $width = 120;                #图片宽度
    private $height = 40;                #图片高度
    private $font = 'font/elephant.ttf'; #字体文件路径
    private $fontsize = 14;              #字体大小
    private $strlen = 6;                 #字符个数
    private $auth_code_str = null;       #验证码结果
    private $imgresult = null;           #图片资源

    #入口文件 静态方法调用 实例化对象 可用 对象方法调用
    public static function img()
    {
        if (!(self::$instance instanceof self)) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    #随机颜色
    private function randomcolor($img = null, $min = 0, $max = 255)
    {
        $rgb = [];
        for ($i = 1; $i <= 3; $i++) {
            $rgb[] = str_pad(rand($min, $max), 3, 0, str_pad_left);
        }
        return imagecolorallocate($img, $rgb[0], $rgb[1], $rgb[2]);
    }

    #随机字符串
    private function randomstr($num = 4)
    {
        if ($num > 0) {
            $string = array_merge(range('a', 'z'), range(0, 9), range('a', 'z'), range(0, 9));
            for ($i = 1; $i <= $num; $i++) {
                shuffle($string);
                $this->auth_code_str .= array_pop($string);
            }
        }
        return $this;
    }

    #创建验证码
    public function createauthcode(&$codestr = false)
    {
        if (!$this->auth_code_str) {
            $this->randomstr($this->strlen);
        }
        if ($codestr !== false && empty($codestr)) {
            $codestr = $this->auth_code_str;
        } else if (!empty($codestr) && $codestr !== false) {
            $this->auth_code_str = $codestr;
        }
        $this->imgresult = imagecreatetruecolor($this->width, $this->height);
        $background = $this->randomcolor($this->imgresult, 200);
        imagefilledrectangle($this->imgresult, 0, 0, $this->width, $this->height, $background);
        $y = ($this->height - $this->fontsize);
        $string = str_split($this->auth_code_str, 1);
        for ($i = 0; $i < count($string); $i++) {
            $frontcolor = $this->randomcolor($this->imgresult, 0, 200);
            imagefttext($this->imgresult, $this->fontsize, rand(0, 10), ($this->fontsize + 2) * $i + 10, $y, $frontcolor, $this->font, $string[$i]);
        }
        return $this;
    }

    #生成线
    public function line($line = 3)
    {
        $line = $line ?: 3;
        for ($i = 1; $i <= $line; $i++) {
            $linecolor = $this->randomcolor($this->imgresult, 0, 200);
            imageline($this->imgresult, rand(0, $this->width / 5), rand(5, $this->height - 5), rand($this->width / 1.3, $this->width), rand(5, $this->height - 5), $linecolor);
        }
        return $this;
    }

    #噪点
    public function pixel($num = 50){
        $num = $num ?: 3;
        for ($i = 1; $i <= $num; $i++) {
            $linecolor = $this->randomcolor($this->imgresult, 0, 100);
            imagesetpixel($this->imgresult, rand(0, $this->width), rand(0, $this->height), $linecolor);
        }
        return $this;
    }

    #设置大小
    public function size($width = null, $height = null)
    {
        $this->width = $width ?: 120;
        $this->height = $height ?: 40;
        return $this;
    }

    #设置字体大小
    public function fontsize($fontsize = 14)
    {
        $this->fontsize = $fontsize ?: 14;
        return $this;
    }

    #设置字体
    public function font($file = null)
    {
        if (is_null($file) === true) {
            $this->font = 'font/elephant.ttf';
        } else {
            $this->font = $file;
        }
        return $this;
    }

    #设置长度
    public function strlen($num = null)
    {
        $this->strlen = $num ?: 6;
        return $this;
    }

    #显示图片
    public function display()
    {
        ob_end_flush();
        header("content-type:image/jpeg");
        imagejpeg($this->imgresult, null, 100);
        imagedestroy($this->imgresult);
        exit;
    }
}

#简单调用方法
authcode::img()->createauthcode()->display();
/*
#指定字符串调用
$string = 'abc123';
authcode::img()->createauthcode($string)->display();

#设置图片大小、字数、字体大小
authcode::img()->strlen(8)->size(300,100)->fontsize(30)->createauthcode()->display();

#添加噪点
authcode::img()->createauthcode()->line()->pixel()->display();
*/