PHP Verification Code Class

<?php/** * Created by Phpstorm. * User:administrator * DATE:2016/6/20 * time:14:29 */class captcha{//Verification code class protected $str = "XAAXQWE556232ASSD"  ; Random number protected $code; Verification Code protected $length = 4;  Verification code Length protected $width = 80; Verification code Width Protected $height = 30;        Verification code height protected $img;//verification code generation//Random number Public Function GetCode () {$len =strlen ($this->str)-1;        for ($i =0; $i <4; $i + +) {$this->code.= $this->str[mt_rand (0, $len)]; }}//Generate background Public function CODEBG () {//Create a new image $this->img=imagecreatetruecolor ($this->width        , $this->height);  $color =imagecolorallocate ($this->img,rand (1,100), rand (1,100), rand (1,100));        Red, green, blue//$back =imagecolorallocate ($this->img,0,0,0);    Imagefilledrectangle ($this->img,0,0, $this->width, $this->height, $color);         }//Generate interference element public function Setline () {//Interference point for ($i =0; $i <1000; $i + +) {   $color =imagecolorallocate ($this->img,rand (0,255), Rand (0,255), Rand (0,255));        Imagesetpixel ($this->img,rand (1,99), Rand (1,99), $color); }//////Interference line for ($i =0; $i <5; $i + +) {$color =imagecolorallocate ($this->img,rand (0,255), R            and (0,255), Rand (0,255)); Imageline ($this->img,rand (0, $this->width), rand (0, $this->height), rand (0, $this->width), rand (0, $this-        >height), $color);    }//////Interference line}//Generate element Header public Function Outheader () {Header ("content-type:image/png");        }//write Verification code Public Function WriteString () {$red = Imagecolorallocate ($this->img, 255, 0, 0);        Imagestring ($this->img,5,rand (1,15), Rand (1,15), $this->code (), $red);        $font = ' Arial.ttf ';    Imagettftext ($this->img, 0, ten, $red, $font, $this->code);        }//shu Public Function png () {$this->outheader (); $this-&GT;CODEBG ();        $this->getcode ();        $this->setline ();        $this->writestring ();        Session_Start ();        $_session[' code ']= $this->code ();    Imagepng ($this->img);    Public Function code () {return strtoupper ($this->code); }} $ce =new captcha (); $ce->png (); Var_dump ($_session[' code ');

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PHP Verification Code Class