PHP生成图形验证码

<?php

/**
 * @name CheckNum_Class.php
 * @abstract 生成验证码类，验证码由随机字母和随机数组成
 * @author 感染源
 * @copyright 2007
 */

class CheckNum_Class
{
    //初始验证码数组
    private $VerifyStr = array(
    'Q','W','E','E','T','Y','U','I','O','P','A','S','D','F',
    'G','H','J','K','L','Z','X','C','V','B','N','M','0','1',
    '2','3','4','5','6','7','8','9');
    private $ArrayId;                //初始验证码数组下标
    private $VerifyStrLen;            //初始验证码长度
    private $R_VerifyStr = '';        //返回验证码
    private $R_VerifyStrLen;        //返回验证码的长度
    
    private $Im;                    //图像操作标识
    private $BgColor;                //图像背景颜色
    private $ImWidth;                //图像宽度
    private $ImHeight;                //图像高度
    
    private $FontSize;                //验证码大小
    private $FontX;                    //验证码显示起始X位置
    private $FontY;                    //验证码显示起始Y位置
    private $FontColor;                //验证码颜色
    
    private $PixColor;                //干扰符颜色
    private $PixX;                    //干扰符位置
    private $PixY;                    //干扰符位置
    private $PixAmount;                //干扰度
    
    
    function __construct($pImSet)
    {
        /*
         * @var array $pImSet
        */
        
        $this->ImWidth   = $pImSet['w'];    //宽
        $this->ImHeight  = $pImSet['h'];    //高
        $this->PixAmount = $pImSet['p'];     //干扰度
        
        $this->Im = imagecreate($this->ImWidth,$this->ImHeight);    //建立画布
        
        //设置背景色
        $this->BgColor = imagecolorallocate($this->Im,$pImSet['r'],$pImSet['g'],$pImSet['b']);
    }
    
    
    function __destruct()
    {
        imagedestroy($this->Im);
    }
    
    
    function Show_Verify($pFont)
    {
        /*
         * @var array $pFont
        */
        
        header("Content-type:image/png");
        $this->FontSize  = $pFont['s'];        //验证码文字大小
        
        //设置验证码显示颜色
        $this->FontColor = imagecolorallocate($this->Im,$pFont['r'],$pFont['g'],$pFont['b']);
        $this->R_VerifyStrLen = $pFont['l'];//验证码显示位数
        $this->VerifyStrLen   = count($this->VerifyStr);
        
        //验证码输入位置
        $this->FontX    = round($this->FontSize/2);
        $this->FontY    = round($this->FontSize/2);
        
        //生成验证码
        for($i=0;$i<$this->R_VerifyStrLen;$i++)
        {
            $this->ArrayId = rand(0,($this->VerifyStrLen-1));
            $this->R_VerifyStr .= $this->VerifyStr[$this->ArrayId];
        }
        
        //在图片显示验证码
        imagestring($this->Im,$this->FontSize,$this->FontX,$this->FontY,$this->R_VerifyStr,$this->FontColor);
        
        
        //生成干扰点
        for($j=0;$j<$this->PixAmount;$j++)
        {
            $this->PixX     = rand(0,$this->ImWidth);
            $this->PixY     = rand(0,$this->ImHeight);
            $this->PixColor = imagecolorallocate($this->Im,rand(0,255),rand(0,255),rand(0,255));
            imagesetpixel($this->Im,$this->PixX,$this->PixY,$this->PixColor);
        }
        
        imagepng($this->Im);        //输入验证码图片
    }
    
    
    function Get_Verify()
    {
        return $this->R_VerifyStr;    //返回验证码
    }
}

//TestCode
$pImset = array('w'=>55,'h'=>25,'p'=>140,'r'=>130,'g'=>160,'b'=>180);
$img = new CheckNum_Class($pImset);
$pFont = array('s'=>10,'r'=>0,'g'=>0,'b'=>255,'l'=>5);
$img->Show_Verify($pFont);
$img = NULL;
?>