PHP编写的图片验证码类文件分享_php实例

适用于自定义的验证码类！

code_len;$i++ ){
      $code .= $this->code_str[mt_rand(0, strlen($this->code_str)-1)];
  }
    return $this->code = $code;
  }
   
  //输出图像
  public function getImage(){
    $w = $this->width;
    $h = $this->height;
    $bg_color = $this->bg_color;
    $img = imagecreatetruecolor($w, $h);
    $bg_color = imagecolorallocate($img, 
  hexdec(substr($bg_color, 1,2)), hexdec(substr($bg_color, 3,2)), hexdec(substr($bg_color, 5,2)));
  imagefill($img, 0, 0, $bg_color);
    $this->img = $img;
    $this->create_font();
    $this->create_pix();
  $this->show_code();
  }
 
 
  //写入验证码
  public function create_font(){
    $this->create_code();
    $color = $this->font_color;
    $font_color = imagecolorallocate($this->img, hexdec(substr($color,1,2)), hexdec(substr($color, 3,2)), hexdec(substr($color,5,2)));
    $x = $this->width/$this->code_len;
    for( $i=0;$icode_len;$i++ ){
      $txt_color = imagecolorallocate($this->img, mt_rand(0,100), mt_rand(0, 150), mt_rand(0, 200));
      imagettftext($this->img, $this->font_size, mt_rand(-30, 30), $x*$i+mt_rand(3, 6), mt_rand($this->height/1.2, $this->height), $txt_color, $this->font , $this->code[$i]); 
      //imagestring($this->img, $this->font_size, $x*$i+mt_rand(3, 6),mt_rand(0, $this->height/4) , $this->code[$i], $font_color);
    }
    $this->font_color = $font_color;
  }
   
  //画干扰线
  public function create_pix(){
    $pix_color= $this->font_color;
    for($i=0;$iimg, mt_rand(0, $this->width),mt_rand(0, $this->height), $pix_color);
    }
    for($j=0;$jimg, mt_rand(1, 2));
      imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $pix_color);
    }
  }
   
  //得到验证码
  public function getCode(){
    return strtoupper($this->code);
  }
 
 
  //输出验证码
  private function show_code(){
    header("Content-type:image/png");
    imagepng($this->img);
    imagedestroy($this->img);
  }
}

我们再来看一例代码：

生成图片类型验证码，验证码包含数字和大写字母，session中存放md5加密后的验证码

buildAndExportImage();
 * 
 * 作     者: luojing
 * 创建时间: 2013-3-27 上午11:42:12
 */
class Captcha {
	
	private $width;//宽度
	private $height; //高度
	private $codeNum;//验证码字符数量
	private $image;//验证码图像资源
	private $sessionKey;//session中保存的名字
	private $captcha;//验证码字符串
	const charWidth = 10;//单个字符宽度,根据输出字符大小而变
	
	/**
	 * 创建验证码类，初始化相关参数
	 * @param $width 图片宽度
	 * @param $height 图片高度
	 * @param $codeNum 验证码字符数量
	 * @param $sessionKey session中保存的名字
	 */
	function __construct($width = 50, $height = 20, $codeNum = 4, $sessionKey = 'captcha') {
		$this->width = $width;
		$this->height = $height;
		$this->codeNum = $codeNum;
		$this->sessionKey = $sessionKey;
		
		//保证最小高度和宽度
		if($height height = 20;
		}
		if($width width = $codeNum * self::charWidth + 10;
		}
	}
	
	/**
	 * 构造并输出验证码图片
	 */
	public function buildAndExportImage() {
		$this->createImage();
		$this->setDisturb();
		$this->setCaptcha();
		$this->exportImage();
	}
	
	/**
	 * 构造图像，设置底色
	 */
	private function createImage() {
		//创建图像
		$this->image = imagecreatetruecolor($this->width, $this->height); 
		//创建背景色
		$bg = imagecolorallocate($this->image, mt_rand(220, 255), mt_rand(220, 255), mt_rand(220, 255)); 
		//填充背景色
		imagefilledrectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $bg);
	}
	
	/**
	 * 设置干扰元素
	 */
	private function setDisturb() {
		
		//设置干扰点
		for($i = 0; $i image, mt_rand(150, 200), mt_rand(150, 200), mt_rand(150, 200));
			imagesetpixel($this->image, mt_rand(5, $this->width - 10), mt_rand(5, $this->height - 3), $color);
		}
		
		//设置干扰线
		for($i = 0; $i image, mt_rand(150, 220), mt_rand(150, 220), mt_rand(150, 220));
			imagearc($this->image, mt_rand(-10, $this->width), mt_rand(-10, $this->height), mt_rand(30, 300), mt_rand(20, 200), 55, 44, $color);
		}
		
		//创建边框色
		$border = imagecolorallocate($this->image, mt_rand(0, 50), mt_rand(0, 50), mt_rand(0, 50));
		//画边框
		imagerectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $border);
	}
	
	/**
	 * 产生并绘制验证码
	 */
	private function setCaptcha() {
		$str = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
		//生成验证码字符
		for($i = 0; $i codeNum; $i++) {
			$this->captcha .= $str{mt_rand(0, strlen($str) - 1)};
		}
		//绘制验证码
		for($i = 0; $i captcha); $i++) {
			$color = imagecolorallocate($this->image, mt_rand(0, 200), mt_rand(0, 200), mt_rand(0, 200));
			$x = floor(($this->width - 10)/$this->codeNum);
			$x = $x*$i + floor(($x-self::charWidth)/2) + 5;
			$y = mt_rand(2, $this->height - 20);
			imagechar($this->image, 5, $x, $y, $this->captcha{$i}, $color);
		}
	}
	
	/*
	 * 输出图像,验证码保存到session中
	 */
	private function exportImage() {
		if(imagetypes() & IMG_GIF){
			header('Content-type:image/gif');
			imagegif($this->image);
		} else if(imagetypes() & IMG_PNG){
			header('Content-type:image/png'); 
     	imagepng($this->iamge);
		} else if(imagetypes() & IMG_JPEG) {
			header('Content-type:image/jpeg'); 
     	imagepng($this->iamge);
		} else {
			imagedestroy($this->image);
			die("Don't support image type!");
		}
		//将验证码信息保存到session中，md5加密
		if(!isset($_SESSION)){
  		session_start();
		} 
		$_SESSION[$this->sessionKey] = md5($this->captcha);
		
    imagedestroy($this->image); 
	}
	
	function __destruct() {
		unset($this->width, $this->height, $this->codeNum,$this->captcha);
	}
}

例三：

width=$width;
  $this->height=$height;
  $this->codeNum=$codeNum;
  $this->checkCode=$this->createCheckCode();
  $number=floor($width*$height/15);
 
  if($number > 240-$codeNum){
  $this->disturbColorNum= 240-$codeNum;
  }else{
  $this->disturbColorNum=$number;
  }
 
 }
 //通过访问该方法向浏览器中输出图像
 function showImage($fontFace=""){
  //第一步：创建图像背景
  $this->createImage();
  //第二步：设置干扰元素
  $this->setDisturbColor();
  //第三步：向图像中随机画出文本
  $this->outputText($fontFace);
  //第四步：输出图像
  $this->outputImage();
 }
 
 //通过调用该方法获取随机创建的验证码字符串
 function getCheckCode(){
  return $this->checkCode;
 }
 private function createImage(){
  //创建图像资源
  $this->image=imagecreatetruecolor($this->width, $this->height);
  //随机背景色
  $backColor=imagecolorallocate($this->image, rand(225, 255), rand(225,255), rand(225, 255));
  //为背景添充颜色
  imagefill($this->image, 0, 0, $backColor);
  //设置边框颜色
  $border=imagecolorallocate($this->image, 0, 0, 0);
  //画出矩形边框
  imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $border);
 }
 private function setDisturbColor(){
  for($i=0; $idisturbColorNum; $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; $iimage, rand(200, 255), rand(200, 255), rand(200, 255));
  imagearc($this->image, rand(-10, $this->width), rand(-10, $this->height), rand(30, 300), rand(20, 200), 55, 44, $color);
  }
 }
 private function createCheckCode(){

//这里主要产生随机码，从2开始是为了区分1和l
  $code="23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKMNPQRSTUVWXYZ";
  $string='';
  for($i=0; $i codeNum; $i++){
  $char=$code{rand(0, strlen($code)-1)};
  $string.=$char;
  }
  return $string;
 }
 private function outputText($fontFace=""){
  for($i=0; $icodeNum; $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+3;
   $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+5, $this->height);
   imagettftext($this->image,$fontsize,rand(-30, 30),$x,$y ,$fontcolor, $fontFace, $this->checkCode{$i});
  }
  }
 }
 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不支持图像创建");
  }
 }
 function __destruct(){
  imagedestroy($this->image);
 }
 }
 

使用如下：

测试，调用验证码类
code.php

showImage();  //输出到页面* 注册或登录使用
$_SESSION["code"]=$code->getCheckCode(); //将验证码保存到服务器中