PHP制作图形验证码代码分享

效果：

myvcode.class.php：封装创建验证码的类

<?php/** file:myvcode.class.php* 验证码类,类名Vcode*/class Vcode{private $width;              /*验证码宽度*/private $height;             /*验证码高度*/private $codeNum;            /*验证码字符个数*/private $checkCode;            /*验证码字符*/private $image;                /*验证码资源*/private $pixNum;            /*绘制干扰点的个数*/private $lineNum;            /*绘制干扰线的条数*/

/**构造方法实例化验证码对象，并初始化数据*@param int $width         设置默认宽度*@param int $height     设置默认高度*@param int $codeNum    设置验证码中的字符个数*@param int $pixNum        设置干扰点的个数*@param int $lineNum    设置干扰线的数量*/function __construct($width=80,$height=40,$codeNum=4,$pixNum=40,$lineNum=5){$this->width = $width;$this->height = $height;$this->codeNum = $codeNum;$this->pixNum = $pixNum;$this->lineNum = $lineNum;}/*内部私有方法,创建图像资源*/private function getCreateImage(){$this->image = imagecreatetruecolor($this->width, $this->height);$white = imagecolorallocate($this->image,0xff,0xff,0xff);imagefill($this->image, 0, 0, $white);$black = imagecolorallocate($this->image,0,0,0);imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $black);}/*内部私有方法,绘制字符，去掉o0Llz和012*/private function createCheckCode(){$code = '3456789abcdefghijkmnpqrstuvwxyABCDEFGHIJKMNPQRSTUVWXY';$this->checkCode = "";for($i=0; $i<$this->codeNum;$i++){$char = $code{rand(0,strlen($code) - 1)};$this->checkCode .= $char;$fontColor = imagecolorallocate($this->image, rand(0,128), rand(0,128),rand(0,128));$fontSize = rand(3,5);$x = rand(0,$this->width-imagefontwidth($fontSize));$y = rand(0,$this->height-imagefontheight($fontSize));imagechar($this->image, $fontSize, $x, $y, $char, $fontColor);}}/*内部私有方法设置干扰元素*/private function setDisturbColor(){/*绘制干扰点*/for($i=0; $i<$this->pixNum; $i++){$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), $color);}/*绘制干扰线*/for($i=0; $i<$this->lineNum; $i++){$color = imagecolorallocate($this->image, rand(0,255), rand(0,255), rand(0,255));imageline($this->image, rand(1,$this->width / 2), rand(1,$this->height / 2),rand($this->width / 2,$this->width – 2), rand($this->height / 2,$this->height – 2), $color);

}}/*开启session保存 利用echo 输出图像*/function __toString(){$_SESSION['code'] = strtoupper($this->checkCode);$this->getCreateImage();$this->createCheckCode();$this->setDisturbColor();$this->outputImg();}/*内部私有方法输出图像*/private function outputImg(){header("content-type:image/png");imagepng($this->image);}/*析构方法，释放对象*/function __destruct(){imagedestroy($this->image);}}?>

imgcode.php输出图像

<?php
session_start();
require_once('myvcode.class.php');
echo new Vcode();
?>

test.html:同过img标签引用

<img src="imgcode.php">

可以加一个a标签，用js实现换一张效果：

/*局部刷新换验证码*/
function changeCode()
{
var imgcode = document.getElementById(‘code');
var change = document.getElementById(‘change');
change.onclick = function()
{
/*必须加后面的参数才能刷新*/
imgcode.src='code.php?tm'+Math.random();
}
}

code和change分别是img和a的id