<"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;    
  }
}
?>