个人写的PHP验证码生成类分享

此验证码类直接拿去就可以用，也可以参考！

其中类成员codestr是生成的验证码字符串:

    <?php
    /**
     * 验证码
     */
    class Code{

      // 1. 定义各个成员 有宽、高、画布、字数、类型、画类型

      private $width; //宽度
      private $height; //高度
      private $num; //验证码字数
      private $imgType; //生成图片类型
      private $Type; //字串类型 1,2,3 三个选项 1 纯数字 2 纯小写字母 3 大小写数字混合
      private $hb; //画布
      public $codestr; // 验证码字串

      public function __construct($height=20,$num=4,$imgType="jpeg",$Type=1){
        $this->width = $num*20;
        $this->height = $height;
        $this->num = $num;
        $this->imgType = $imgType;  
        $this->Type = $Type; 
        $this->codestr = $this->codestr();
        $this->zuhe();
      }

      // 2. 定义随机获取字符串函数
      private function codestr(){
        switch($this->Type){

          case 1:   // 类型为1 获取1-9随机数
            $str = implode("",array_rand(range(0,9),$this->num));
            break;
          case 2:   // 类型为2 获取a-z随机小写字母
            $str = implode("",array_rand(array_flip(range(a,z)),$this->num));
            break;
          case 3:   // 类型为3 获取数字,小写字母,大写字母 混合
            for($i=0;$i<$this->num;$i++){
              $m = rand(0,2);
              switch($m){
                case 0:
                  $o = rand(48,57);
                  break;
                case 1:
                  $o = rand(65,90);
                  break;
                case 2:
                  $o = rand(97,122);
                  break; 
              }
              $str .= sprintf("%c",$o);
            }
            break;     
        }


        return $str;  
      }


      // 3. 初始化画布图像资源
      private function Hb(){
        $this->hb = imagecreatetruecolor($this->width,$this->height); 
      }

      // 4. 生成背景颜色
      private function Bg(){
        return imagecolorallocate($this->hb,rand(130,250),rand(130,250),rand(130,250)); 
      }

      // 5. 生成字体颜色
      private function Font(){
        return imagecolorallocate($this->hb,rand(0,100),rand(0,100),rand(0,100));  
      }

      // 6. 填充背景颜色
      private function BgColor(){
        imagefilledrectangle($this->hb,0,0,$this->width,$this->height,$this->Bg()); 
      }

      // 7. 干扰点
      private function ganrao(){
        $sum=floor(($this->width)*($this->height)/3);
        for($i=0;$i<$sum;$i++){
          imagesetpixel($this->hb,rand(0,$this->width),rand(0,$this->height),$this->Bg());  
        }
      }

      // 8. 随机直线 弧线
      private function huxian(){
        for($i=0;$i<$this->num;$i++){
          imageArc($this->hb,rand(0,$this->width),rand(0,$this->height),rand(0,$this->width),rand(0,$this->height),rand(0,360),rand(0,360),$this->Bg());    
        }  
      }

      // 9. 写字
      private function xiezi(){
        for($i=0;$i<$this->num;$i++){
          $x=ceil($this->width/$this->num)*$i; 
          $y=rand(1,$this->height-15);
          imagechar($this->hb,5,$x+4,$y,$this->codestr[$i],$this->Font());
        }  
      }

      // 10. 输出
      private function OutImg(){
        $shuchu="image".$this->imgType; 
        $header="Content-type:image/".$this->imgType;
        if(function_exists($shuchu)){
          header($header);
          $shuchu($this->hb); 
        }else{
          exit("GD库没有此类图像"); 
        }
      }

      // 11. 拼装
      private function zuhe(){
        $this->Hb();
        $this->BgColor();
        $this->ganrao();
        $this->huxian();
        $this->xiezi();
        $this->OutImg(); 
      }  

      public function getCodeStr(){
        return $this->codestr;    
      }
    }
    ?>