php实现点击可刷新验证码

5年以前 | 阅读数：658 次 | 编程语言：PHP

验证码类文件 CreateImg.class.php


    <?php 

    class ValidationCode 
    { 
    private $width,$height,$codenum; 
    public $checkcode;   //产生的验证码 
    private $checkimage;  //验证码图片 
    private $disturbColor = ''; //干扰像素 

    function __construct($width='80',$height='20',$codenum='4') 
    { 
      $this->width=$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


    <?php 
    session_start(); 
    require_once('CreateImg.class.php'); 
    $image = new ValidationCode('80','20','4');  //图片长度、宽度、字符个数 
    $image->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'; 
    } 
    } 
    ?> 

    <html> 
    <head> 
    <title>Image</title> 
    <meta http-equiv="content-type" content="text/html;charset=utf-8"> 
    <script language="javascript"> 
    function newgdcode(obj,url) { 
    obj.src = url+ '?nowtime=' + new Date().getTime(); 
    //后面传递一个随机参数，否则在IE7和火狐下，不刷新图片 
    } 
    </script> 
    <body> 
    <img src="imgcode.php" alt="看不清楚，换一张" align="absmiddle" style="cursor: pointer;" onclick="javascript:newgdcode(this,this.src);" /> 
    <form method="POST" name="form1" action="image.php"> 
    <input type="text" name="test"> 
    <br /> 
    <input type="submit" name="submit" value="提交"> 
    </form> 
    </body> 
    </head> 
    </html>

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。