一个php验证码的封装类

<?php
/**
* 验证码类
* edit www.jb200.com
*/
class ValidationCode {
private $width;
private $height;
private $codeNum;
private $image; //图像资源
private $disturbColorNum;
private $checkCode;
function __construct($width=80, $height=20, $codeNum=4){
$this->width=$width;
$this->height=$height;
$this->codeNum=$codeNum;
$this->checkCode=$this->createCheckCode();
$number=floor($width*$height/15);

if($number > 240-$codeNum){
$this->disturbColorNum= 240-$codeNum;
}else{
$this->disturbColorNum=$number;
}

}
//通过访问该方法向浏览器中输出图像
function showImage($fontFace=""){
//第一步：创建图像背景
$this->createImage();
//第二步：设置干扰元素
$this->setDisturbColor();
//第三步：向图像中随机画出文本
$this->outputText($fontFace);
//第四步：输出图像
$this->outputImage();
}

//通过调用该方法获取随机创建的验证码字符串
function getCheckCode(){
return $this->checkCode;
}
private function createImage(){
//创建图像资源 //www.jb200.com
$this->image=imagecreatetruecolor($this->width, $this->height);
//随机背景色
$backColor=imagecolorallocate($this->image, rand(225, 255), rand(225,255), rand(225, 255));
//为背景添充颜色
imagefill($this->image, 0, 0, $backColor);
//设置边框颜色
$border=imagecolorallocate($this->image, 0, 0, 0);
//画出矩形边框
imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $border);
}
private function setDisturbColor(){
for($i=0; $i<$this->disturbColorNum; $i++){
$color=imagecolorallocate($this->image, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($this->image, rand(1, $this->width-2), rand(1, $this->height-2), $color);
}
for($i=0; $i<10; $i++){
$color=imagecolorallocate($this->image, rand(200, 255), rand(200, 255), rand(200, 255));
imagearc($this->image, rand(-10, $this->width), rand(-10, $this->height), rand(30, 300), rand(20, 200), 55, 44, $color);
}
}
private function createCheckCode(){
//这里主要产生随机码，从2开始是为了区分1和l
$code="23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKMNPQRSTUVWXYZ";
$string='';
for($i=0; $i < $this->codeNum; $i++){
$char=$code{rand(0, strlen($code)-1)};
$string.=$char;
}
return $string;
}
private function outputText($fontFace=""){
for($i=0; $i<$this->codeNum; $i++){
$fontcolor=imagecolorallocate($this->image, rand(0, 128), rand(0, 128), rand(0, 128));
if($fontFace==""){
$fontsize=rand(3, 5);
$x=floor($this->width/$this->codeNum)*$i+3;
$y=rand(0, $this->height-15);
imagechar($this->image,$fontsize, $x, $y, $this->checkCode{$i},$fontcolor);
}else{
$fontsize=rand(12, 16);
$x=floor(($this->width-8)/$this->codeNum)*$i+8;
$y=rand($fontSize+5, $this->height);
imagettftext($this->image,$fontsize,rand(-30, 30),$x,$y ,$fontcolor, $fontFace, $this->checkCode{$i});
}
}
}

//输出图象信息
private function outputImage() {
if(imagetypes() & IMG_GIF){
header("Content-Type:image/gif");
imagepng($this->image);
}else if(imagetypes() & IMG_JPG){
header("Content-Type:image/jpeg");
imagepng($this->image); //www.jb200.com
}else if(imagetypes() & IMG_PNG){
header("Content-Type:image/png");
imagepng($this->image);
}else if(imagetypes() & IMG_WBMP){
header("Content-Type:image/vnd.wap.wbmp");
imagepng($this->image);
}else{
die("PHP不支持图像创建");
}
}
function __destruct(){
imagedestroy($this->image);
}
}
?>

<?php
session_start();
include "validationcode.class.php";
$code=new ValidationCode(80, 20, 4);
$code->showImage(); //输出到页面中供 注册或登录使用
$_SESSION["code"]=$code->getCheckCode(); //将验证码保存到服务器中
?>