php实现点击可刷新验证码

本文实例为大家分享了php点击可刷新验证码的具体代码，供大家参考，具体内容如下

验证码类文件 CreateImg.class.php

width=$width; 
 $this->height=$height; 
 $this->codenum=$codenum; 
} 
function outImg() 
{ 
 //输出头 
 $this->outFileHeader(); 
 //产生验证码 
 $this->createCode(); 
 
 //产生图片 
 $this->createImage(); 
 //设置干扰像素 
 $this->setDisturbColor(); 
 //往图片上写验证码 
 $this->writeCheckCodeToImage(); 
 imagepng($this->checkimage); 
 imagedestroy($this->checkimage); 
} 
 
private function outFileHeader() 
{ 
 header ("Content-type: image/png"); 
} 
 
private function createCode() 
{ 
 $this->checkcode = strtoupper(substr(md5(rand()),0,$this->codenum)); 
} 
 
private function createImage() 
{ 
 $this->checkimage = @imagecreate($this->width,$this->height); 
 $back = imagecolorallocate($this->checkimage,255,255,255); 
 $border = imagecolorallocate($this->checkimage,0,0,0); 
 imagefilledrectangle($this->checkimage,0,0,$this->width - 1,$this->height - 1,$back); // 白色底 
 imagerectangle($this->checkimage,0,0,$this->width - 1,$this->height - 1,$border); // 黑色边框 
} 
 
private function setDisturbColor() 
{ 
 for ($i=0;$i<=200;$i++) 
 { 
 $this->disturbColor = imagecolorallocate($this->checkimage, rand(0,255), rand(0,255), rand(0,255)); 
 imagesetpixel($this->checkimage,rand(2,128),rand(2,38),$this->disturbColor); 
 } 
} 
 
private function writeCheckCodeToImage() 
{ 
 for ($i=0;$i<=$this->codenum;$i++) 
 { 
 $bg_color = imagecolorallocate ($this->checkimage, rand(0,255), rand(0,128), rand(0,255)); 
 $x = floor($this->width/$this->codenum)*$i; 
 $y = rand(0,$this->height-15); 
 imagechar ($this->checkimage, rand(5,8), $x, $y, $this->checkcode[$i], $bg_color); 
 } 
} 
function __destruct() 
{ 
 unset($this->width,$this->height,$this->codenum); 
} 
} 
?> 

包含文件imgcode.php

outImg(); 
$_SESSION['validationcode'] = $image->checkcode; //存贮验证码到 $_SESSION 中 
?>

前台文件 demo.php

?php 
session_start(); 
$test = $_POST['test']; 
$test = strtoupper(trim($test)); 
$submit = $_POST['submit']; 
if(isset($submit)){ 
if($test==$_SESSION['validationcode']){ 
 echo 'true'; 
} else { 
 echo 'false'; 
} 
} 
?> 
 
 
 
 
 
 
 
 
 
 
 
 

以上就是为大家介绍的php点击验证码即可刷新的全部代码，希望对大家的学习有所帮助。