/* note： * this     指向当前对象本身 * self     指向当前类 * parent   指向父类 *//* 验证码工具类 * @author pandancode * @date 20150-12-1 */class Verification_Code{        private $_vode;    private $_vode_len;    private $_img_handle;    private $_img_width;    private $_img_height;    private $_img_type;    private $_img_bg_color;    private $_img_color;        /* 单实例 */    private static $_instance;        /* 获取当前实例 */    public static function getInstance(){        if( !(self::$_instance instanceof self) ){            self::$_instance = new self;        }        return self::$_instance;    }        /* 构造函数,设置 为private，禁止外部访问 */    private function __Construct(){}        /* 设置 为private，禁止外部访问,禁止外部访问 */    private function __clone(){}        /* 生成验证码图片前设置参数     * @param string vode 验证码      * @param int vode_len 验证码长度      * @param string img_type 生成图片格式，默认为png      */    public function set_param($vode,$vode_len,$width,$height,$img_type='png',$img_bg_color=array('R'=>250,'G'=>'250','B'=>'250'),$img_color=array('R'=>0,'G'=>0,'B'=>0)){        $this->_vode = $vode;        $this->_vode_len = $vode_len;        $this->_img_width = $width;        $this->_img_height = $height;        $this->_img_type = $_img_type;        $this->_img_bg_color = $img_bg_color;        $this->_img_color = $img_color;    }        /* 生成图片      */    public function create_img(){        $this->_img_handle = ImageCreate($this->_img_width,$this->_img_height);        $this->_img_bg_color = ImageColorAllocate($this->_img_handle,$this->_img_bg_color['R'],$this->_img_bg_color['G'],$this->_img_bg_color['B']);        $this->_img_color = ImageColorAllocate($this->_img_handle,$this->_img_color['R'],$this->_img_color['G'],$this->_img_color['B']);                //填充背景颜色        Imagefill($this->_img_handle,0,0,$this->_img_bg_color);        ImageString($this->_img_handle,10,10,10,$this->_vode,$this->_img_color);                ob_clean();        header('Content-type:image/png');        Imagepng($this->_img_handle);    }    }$img_tool = Verification_Code::getInstance();$img_tool->set_param('ABVS',4,80,40);$img_tool->create_img();