php实现的加减法验证码代码

代码如下:

<?php

/*图片验证码文件，加减计算方式*/

class ImageCode{

private $Jiashu = 0; //加数或者减数

private $JianShu = 0; //被加数或者被减数

private $YunSuan = ''; //运算符

private $DeShu = 0; //得数

private $String = ''; //字符串样式

private $Img; //图片对象

private $Width = 100; //图片宽度

private $Height = 50; //图片高度

private $Ttf = 'Num.ttf';//字体文件

private $Session = 'code'; //Session变量

private function JiaShu(){

header('Content-type:image/png');

$this -> Jiashu = rand(1, 10);

$this -> JianShu = rand(1, 10);

$this -> YunSuan= $this -> Jiashu > $this -> JianShu ? '-' : '+';

$this -> DeShu = $this -> Jiashu > $this -> JianShu ? $this -> Jiashu - $this -> JianShu : $this -> Jiashu + $this -> JianShu;

}

public function Show( $W = 100, $H = 50, $T = 'Num.ttf', $Code = 'code' ){

$this -> JiaShu();

$this -> String = $this -> Jiashu . $this -> YunSuan . $this -> JianShu . '= ? ';

$this -> Width = $W;

$this -> Height = $H;

$this -> Ttf = $T;

$this -> Session= $Code;

session_start();

$_SESSION[$this -> Session] = $this -> DeShu;

$this -> Images();

}

private function Images(){

$this -> Img = imagecreate($this -> Width, $this -> Height);

$background_color = imagecolorallocate ($this -> Img, 255, 255, 255);

imagecolortransparent($this -> Img, $background_color);

imagettftext($this -> Img, 14, 0, 1, 20, imagecolorallocate ($this -> Img, 0, 0, 0), $this -> Ttf, $this -> String );

$this -> EchoImages();

}

private function EchoImages(){

imagepng($this -> Img);

imagedestroy($this -> Img);

}

}

$ImageCode = new ImageCode;

$ImageCode -> Show(130, 35, 'Num.ttf', 'code');