验证码类

带你体验封装类的简便快捷

知识点：php基本语法

构造方法，析构方法，魔术方法

<?php$code=new code(); $code->outImage();class code{//验证码个数protected $number;protected $codeType;protected $width;protected $height;protected $image;protected $code;//验证码字符串public function __construct($number=4,$codeType=2,$width=100,$height=50){$this->number=$number;$this->codeType=$codeType;$this->width=$width;$this->height=$height;$this->code=$this->createCode();//生成验证码函数//echo $this->code;}public function __destruct(){imagedestory($this->image);//图像销毁应该写到析构方法中}public function __get($name){//魔术方法if($name=='code'){return $this->code;}return false;}protected function createCode(){//通过你的验证码类型给你生成不同的验证switch($this->codeType){case 0://纯数字$code=$this->getNumberCode();break;case 1://纯字母$code=$this->getCharCode();break;case 2://字母和数字$code=$this->getNumCharCode();break;default:die('不支持这种验证码类型');}return $code;}protected function getNumberCode(){$str=join('',range(0,9));return substr(str_shuffle($str),0,$this->number);}protected function getCharCode(){$str=join('',range('a','z'));$str=$str.strtoupper($str);return substr(str_shuffle($str),0,$this->number);}protected function getNumCharCode(){$numStr=join('',range(0,9));$str=join('',range('a','z'));$str=$numStr.$str.strtoupper($str);return substr(str_shuffle($str),0,$this->number);}protected function createImage(){$this->image=imagecreatetruecolor($this->width,$this->height);}protected function fillBack(){imagefill($this->image,0,0,$this->lightColor());}protected function lightColor(){return imagecolorallocate($this->image,mt_rand(130,255),mt_rand(130,255),mt_rand(130,255));}protected function darkColor(){return imagecolorallocate($this->image,mt_rand(0,120),mt_rand(0,120),mt_rand(0,120));}protected function drawChar(){$width=ceil($this->width/$this->number);for($i=0;$i<$this->number;$i++){$x=mt_rand($i*$width+5,($i+1)*$width-5);$y=mt_rand(0,$this->height=15);imagechar($this->image,5,$x,$y,$this->code[$i],$this->darkColor());}}protected function drawDistub(){for($i=0;$i<150;$i++){$x=mt_rand(0,$this->width);$y=mt_rand(0,$this->height);imagesetpixel($this->image,$x,$y,$this->lightColor());}}protected function show(){header('Content-Type:image/png');imagepng($this->image);}public function outImage(){//创建画布，填充背景色，将验证码字符串划到画布中，添加干扰元素，输出并显示$this->createImage();$this->fillBack();$this->drawChar();$this->drawDistub();$this->show();}}?>

步骤：生成验证码，画出验证码（创建画布，填充背景色，将验证码字符串划到画布中，添加干扰元素，输出并显示）