用PHP写一个验证码类，并进行封装。

类名： validationcode.class.php

代码如下：

<?php

 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

   $this->image=imagecreatetruecolor($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});

    }

   }

  }

  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);

   }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);

  }

 }

 

使用如下：

测试，调用验证码类

code.php

<?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