php验证码生成程序代码

PHP验证码并生成图片程序，采用了session识别，稍微改进了一下目前网络上流传的PHP验证码，加入杂点，数字颜色随机显示，控制4位数字显示；话不多说了，程序如下，分享出来。

新建yz.php验证码生成文件：

注意：以下代码需要打开php的GD库，修改php.in文件的配置，把已经注释掉的行之前的分号取消即可：extension=php_gd2.dll。

代码如下

复制代码

<?php
   class ValidationCode
   {
    //属性
    private $width;
    private $height;
    private $codeNum;
       private $image;
    private $disturbColorNum; //干扰元素数目
    private $checkCode;
    function __construct($width=80,$height=20,$codeNum=4)
     {
     $this->width=$width;
     $this->height=$height;
     $this->codeNum=$codeNum;
     $number=floor($width*$height/15);
     if($number>240-$codeNum)
    {
      $this->disturbColorNum=240-$codeNum;
     }else
      {
      $this->disturbColorNum=$number;
      }
      $this->checkCode=$this->createCheckcode();
    }
    function getCheckCode()
    {
           return $this->checkCode;
    }
    private function createImage(){
          $this->image=imagecreatetruecolor($this->width,$this->height);
    $backcolor=imagecolorallocate($this->image,rand(225,255),rand(225,255),rand(255,255));
    imagefill($this->image,0,0,$backcolor);
    $border=imagecolorallocate($this->image,0,0,0);
    imagerectangle($this->image,0,0,$this->width-1,$this->height-1,$border);
    }
    private function setDisturbColor(){
     for($i=0;$i<$this->disturbColorNum;$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);
     }
     for($i=0;$i<10;$i++)
     {
                  $color=imagecolorallocate($this->image,rand(0,255),rand(0,255),rand(0,255));
      imagearc($this->image,rand(-10,$this->width),rand(-10,$this->height),rand(30,300),rand(20,300),55,44,$color);
     }
    }
      private function outputText($fontFace=""){
    for($i=0;$i<$this->codeNum;$i++)
    {
     $fontcolor=imagecolorallocate($this->image,rand(0,128),rand(0,128),rand(0,128));
    if($fontFace=="")
   {
     $fontsize=rand(3,5);
     $x=floor($this->width/$this->codeNum)*$i+5;
     $y=rand(0,$this->height-15);
     imagechar($this->image,$fontsize,$x,$y,$this->checkCode{$i},$fontcolor);
    }
    else
   {
     $fontsize=rand(12,16);
     $x=floor(($this->width-8)/$this->codeNum)*$i+8;
     $y=rand($fontsize,$this->height-8);
     imagettftext($this->image,$fontsize,rand(-45,45),$x,$y,$fontcolor,$fontFace,$this->checkCode{$i});
    }
    }
   }

   private function createCheckCode(){
    $code="23456789abcdefghijkmnpqrstuvwrst";
    $str="";
    for($i=0;$i<$this->codeNum;$i++)
    {
     $char=$code{rand(0,strlen($code)-1)};
     $str.=$char;
    }
    return $str;
   }
   private function outputImage()
    {
    if(imagetypes()&IMG_GIF)
     {
       header("Content-Type:image/gif");
        imagepng($this->image);
     }else if(imagetypes()&IMG_JPG)
     {
        header("Content-Type:image/jpeg");
        imagepng($this->image);
     }else if(imagetypes()&IMG_PNG)
     {
        header("Content-Type:image/png");
      imagepng($this->image);
     }else if(imagetypes()&IMG_WBMP){
                 header("Content-Type:image/vnd.wap.wbmp");
     imagepng($this->image);
     }else
     {
      die("PHP不支持图片验证码");
     }
    }
        //通过该方法向浏览器输出图像
    function showImage($fontFace="")
    {
     //创建图像背景
            $this->createImage();
     //设置干扰元素
           $this->setDisturbColor();
     //向图像中随机画出文本
     $this->outputText($fontFace);
     //输出图像
     $this->outputImage();
    }

到具体调用的地方，用这样的形式：<img src="/yz.php" align="absmiddle" />就可以了；验证的时候验证session：$_SESSION['VCODE']的值就可以了。还可以对以上代码稍微改进，改成两个数字相加求和的形式

补充：Php教程,Php安全