验证码的类及使用

<?php

session_start();

ini_set(‘display_errors‘, ‘Off‘);

class CCheckCodeFile

{

//验证码位数 www.2cto.com

var $mCheckCodeNum  = 4;

//产生的验证码

var $mCheckCode   = ‘‘;

//验证码的图片

var $mCheckImage  = ‘‘;

//干扰像素

var $mDisturbColor  = ‘‘;

//验证码的图片宽度

var $mCheckImageWidth = ‘80‘;

//验证码的图片宽度

var $mCheckImageHeight  = ‘20‘;

//输出头

function OutFileHeader()

{

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

}

//产生验证码

function CreateCheckCode()

{

//$this->mCheckCode = strtoupper(substr(md5(rand()),0,$this->mCheckCodeNum));

$this->mCheckCode = strtoupper(substr(rand(0,9999999999),0,$this->mCheckCodeNum));

session_cache_expire(60);

session_start();

$_SESSION["code_str"] = $this->mCheckCode;

return $this->mCheckCode;

}

//产生验证码图片

function CreateImage()

{

$this->mCheckImage = @imagecreate ($this->mCheckImageWidth,$this->mCheckImageHeight);

imagecolorallocate ($this->mCheckImage, 255, 255, 255);

return $this->mCheckImage;

}

//设置图片的干扰像素

function SetDisturbColor()

{

for ($i=0;$i<=128;$i++)

{

$this->mDisturbColor = imagecolorallocate ($this->mCheckImage, rand(0,255), rand(0,255), rand(0,255));

imagesetpixel($this->mCheckImage,rand(1,100),rand(1,100),$this->mDisturbColor);

}

}

//设置验证码图片的大小\宽\高

function SetCheckImageWH($width,$height)

{

if($width==‘‘||$height==‘‘)return false;

$this->mCheckImageWidth  = $width;

$this->mCheckImageHeight = $height;

return true;

}

//在验证码图片上逐个画上验证码

function WriteCheckCodeToImage()

{

for ($i=0;$i<=$this->mCheckCodeNum;$i++)

{

$bg_color = imagecolorallocate ($this->mCheckImage, rand(0,255), rand(0,255), rand(0,255));

$x = floor($this->mCheckImageWidth/$this->mCheckCodeNum)*$i;

$y = rand(0,$this->mCheckImageHeight-15);

imagechar ($this->mCheckImage, 5, $x, $y, $this->mCheckCode[$i], $bg_color);

}

}

//输出验证码图片

function OutCheckImage()

{

$this ->OutFileHeader();

$this ->CreateCheckCode();

$this ->CreateImage();

$this ->SetDisturbColor();

$this ->WriteCheckCodeToImage();

imagepng($this->mCheckImage);

imagedestroy($this->mCheckImage);

}

}

$c_check_code_image = new CCheckCodeFile();

//$c_check_code_image ->SetCheckImageWH(100,50);//设置显示验证码图片的尺寸

$c_check_code_image->OutCheckImage();

?>

使用方法:

<tr>

<td align="center" valign="middle">验证码</td>

<td align="center" valign="middle"><input name="number" type="text" style="width:80px;">

<img src="code.php" id="yzm" onclick="this.src=‘code.php?abc=‘+Math.random()" alt="图片看不清？点击重新得到验证码" style="cursor:hand;" />

</td>

</tr>

验证是否正确

session_start();

if($_POST["number"] == $_SESSION["code_str"]){

//      echo("验证码正确");

}else{

echo "

<script>

var s=10;

function ok()

{

s--;

document.getElementById(‘tips‘).innerHTML=s;

if(s==0)

{

clearTimeout(t);

history.go(-1);

}

}

var t=setInterval(‘ok()‘,1000);

</script>

" . "请输入的验证码,请重新输入<span id=‘tips‘></span>秒之后，将为您跳转到<a href=\"javascript:history.go(-1)\">上一页</a>";

}