PHP验证码类

<?php 

class verify{

	//随机因子
	private $text = 'abcdefghWddsdffgdWRFJKFJDFjjdfglkdfg883498Jhdsd9345345j340fg343o4j39d9t345j9dtej';

	//验证码句柄资源
	private $code;

	//验证码长度
	private $length = 4;

	//验证码字体大小
	private $size = 20;

	//生成图像的高度
	private $height = 30;

	//验证码字体
	private $font;

	//图像资源句柄
	private $image;

	/**
	 *	构造方法初始化
	 */
	public function __construct(){
		$this->font = './static/fonts/msyh.ttf';
	}

	/**
	 *	生成随机码
	 */
	private function createcode(){
		$textlength = strlen($this->text)-1;
		for($i=0; $i<$this->length; $i++){
			$this->code .= $this->text[rand(0,$textlength)];
		}
	}

	/**
	 *	创建图像
	 */
	private function createimg(){
		//创建画布
		$this->image = imagecreatetruecolor($this->size*$this->length, $this->height);

		//随机背景色
		$color = imagecolorallocate($this->image, rand(0,255), rand(100,255), 175);

		//创建矩形
		imagefilledrectangle($this->image, 0, $this->height, $this->size*$this->length, 0, $color);
	}

	/**
	 *	生成文字
	 */

	private function createtext(){
		for($i=0;$i<$this->length;$i++){
			$color = imagecolorallocate($this->image, 255, 255, 255);
			imagettftext($this->image, $this->size, 0, 2, 25, $color, $this->font, $this->code);
		}

		//设置字符间距
		//imagepsbbox($this->text, $this->font, $this->size);
	}

	/**
	 *	生成干扰线 以及 $string字符
	 */
	private function createline(){
		$string = '--';
		for($i=0; $i<1; $i++){
			$color = imagecolorallocate($this->image, rand(200,255), rand(200,255), rand(200,255));
			imageline($this->image, rand(1,$this->size*$this->length), rand(1,$this->height), rand(1,$this->size*$this->length), rand(1,$this->height), $color);
		}
		for($i=0; $i<10; $i++){
			$color = imagecolorallocate($this->image, rand(0,10), rand(50,150), rand(200,255));
			imagestring($this->image, 1, rand(0,$this->size*$this->length), rand(0,$this->height), $string, $color);
		}
	}

	/**
	 *	输出图像
	 */
	private function outimage(){
		header('content-type:image/png');
		imagepng($this->image);
		imagedestroy($this->image);
	}

	/**
	 *	对外生成验证
	 */
	public function doimage(){
		$this->createimg();
		$this->createcode();
		$this->createtext();
		$this->createline();
		$this->outimage();
	}

	//获取验证码  
	public function getverify() {  
    	return strtolower($this->code);
    }

}

?>