PHP验证码类

jingjihui

class Captcha{
//验证码宽
private $width;
//验证码高度
private $height;
//验证码长度
private $len;
//验证码范围
private $str =  "abcdefghijkmnpqrstuvwxyz23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
//字体地址
private $font_dir = 'F:\phpStudy\PHPTutorial\WWW\php\code\4.ttf';
//验证码资源
private $img;
//验证码字符串
private $code;
public function __construct($config=['width'=>200,'height'=>50,'len'=>4]){
$this->width=$config['width'];
$this->height=$config['height'];
$this->len=$config['len'];
}
public function entry(){
$this->createBg();
$this->getCode();
$this->setCode();
$this->setLine();
$this->setDot();
$this->setBg();
}
//生成画布
private function createBg(){
$this->img = imagecreate($this->width,$this->height);
//分配验证码的背景颜色
imagecolorallocate($this->img,255,255,255);
}
//生成随机字符串
private function getCode(){
for($i=0;$ilen;$i++){
$key = mt_rand(0,strlen($this->str)-1);
$this->code .= $this->str[$key];
}
$this->setSession();
}
//把验证码存入session之后和用户输入的验证码做比较
private function setSession(){
session_start();
$_SESSION['code']=strtolower($this->code);
}
//输出验证码到画布
private function setCode(){
for($i=0;$ilen;$i++){
$font_color = imagecolorallocate($this->img,mt_rand(0,100),mt_rand(0,100),mt_rand(0,100));
$x = ($this->width/$this->len)*$i+5;
$fontSize = mt_rand(18,28);
$fontHeight=imagefontheight($fontSize);
$y=  mt_rand($fontHeight+5,$this->height);
imagettftext($this->img, $fontSize, mt_rand(-25,25), $x, $y, $font_color, $this->font_dir,$this->code[$i]);
}
}
//画干扰线
private function setLine(){
for ($i=0; $i len ; $i++) {
$line_color = imagecolorallocate($this->img,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
imageline($this->img, mt_rand(0,$this->width/$this->len), mt_rand(0,$this->height), mt_rand($this->width-$this->width/$this->len,$this->width),  mt_rand(0,$this->height), $line_color);
}
}
//画干扰点到画布
private function setDot(){
for ($i=0; $i < $this->width ; $i++) {
$dot_color = imagecolorallocate($this->img,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
imagesetpixel($this->img, mt_rand(0,$this->width), mt_rand(0,$this->height), $dot_color);
}
}
//输出成图像
private function setBg(){
ob_end_clean();
header('content-type:image/jpeg');
imagejpeg($this->img);
}
public function __destruct(){
imagedestroy($this->img);
}
}
　　//输出验证码
$captcha = new Captcha();
$captcha->entry();