ThinkPHP 3.2.3 加减乘法验证码类

<?php

namespace Home\Common;
use Think\Verify;

class VerifyProcess extends Verify {

  private $_image   = NULL;     // 验证码图片实例
  private $_color   = NULL;     // 验证码字体颜色

 public function entryProcess($id = ‘‘) {
    // 图片宽(px)
    $this->imageW || $this->imageW = $this->length*$this->fontSize*1.5 + $this->length*$this->fontSize/2;
    // 图片高(px)
    $this->imageH || $this->imageH = $this->fontSize * 2.5;
    // 建立一幅 $this->imageW x $this->imageH 的图像
    $this->_image = imagecreate($this->imageW, $this->imageH); 

    // 设置背景      
    imagecolorallocate($this->_image, $this->bg[0], $this->bg[1], $this->bg[2]);

    // 验证码字体随机颜色
    $this->_color = imagecolorallocate($this->_image, mt_rand(1,150), mt_rand(1,150), mt_rand(1,150));
    // 验证码使用随机字体
    $ttfPath =  $_SERVER[‘DOCUMENT_ROOT‘].‘/ThinkPHP/Library/Think/Verify/‘ . ($this->useZh ? ‘zhttfs‘ : ‘ttfs‘) . ‘/‘;

    if(empty($this->fontttf)){
        $dir = dir($ttfPath);
        $ttfs = array();		
        while (false !== ($file = $dir->read())) {
            if($file[0] != ‘.‘ && substr($file, -4) == ‘.ttf‘) {
                $ttfs[] = $file;
            }
        }
        $dir->close();
        $this->fontttf = $ttfs[array_rand($ttfs)];
    } 
    $this->fontttf = $ttfPath . $this->fontttf;
    
    if($this->useImgBg) {
        $this->_background();
    }
    
    if ($this->useNoise) {
        // 绘杂点
        $this->_writeNoise();
    } 
    if ($this->useCurve) {
        // 绘干扰线
        $this->_writeCurve();
    }
    
    // 绘验证码
    $codeNX = 0; // 验证码第N个字符的左边距

    // 验证码为简单运算
    $a = mt_rand(1,9);
    $b = mt_rand(1,9);
    $operate_array = array(‘+‘, ‘-‘, ‘*‘);
    $key = mt_rand(0, count($operate_array) - 1);
    
    if($operate_array[$key] == ‘+‘) { // 加法
    	$code = $a.‘+‘.$b.‘=‘;
    	$result = intval($a + $b);
    } elseif($operate_array[$key] == ‘-‘) { // 减法
    	$code = max($a,$b).‘-‘.min($a,$b).‘=‘;
    	$result = intval(abs($a - $b));
    } else { // 乘法
    	$code = $a.‘*‘.$b.‘=‘;
    	$result = intval($a * $b);
    }

    $this->length = 4;

    for ($i = 0; $i<$this->length; $i++) {
        $codeNX  += mt_rand($this->fontSize*1.2, $this->fontSize*1.6);
        imagettftext($this->_image, $this->fontSize, mt_rand(-40, 40), $codeNX, $this->fontSize*1.6, $this->_color, $this->fontttf, $code[$i]);
    }

    // 保存验证码
    $key        =   $this->authcode($this->seKey);
    $result       =   $this->authcode($result);
    $secode     =   array();
    $secode[‘verify_code‘] = $result; // 把校验码保存到session
    $secode[‘verify_time‘] = NOW_TIME;  // 验证码创建时间
    session($key.$id, $secode);
       
    header(‘Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate‘);
    header(‘Cache-Control: post-check=0, pre-check=0‘, false);		
    header(‘Pragma: no-cache‘);
    header("content-type: image/png");

    // 输出图像
    imagepng($this->_image);
    imagedestroy($this->_image);	
	}

  /**
   * 画杂点
   * 往图片上写不同颜色的字母或数字
   */
  private function _writeNoise() {
      $codeSet = ‘2345678abcdefhijkmnpqrstuvwxyz‘;
      for($i = 0; $i < 10; $i++){
          //杂点颜色
          $noiseColor = imagecolorallocate($this->_image, mt_rand(150,225), mt_rand(150,225), mt_rand(150,225));
          for($j = 0; $j < 5; $j++) {
              // 绘杂点
              imagestring($this->_image, 5, mt_rand(-10, $this->imageW),  mt_rand(-10, $this->imageH), $codeSet[mt_rand(0, 29)], $noiseColor);
          }
      }
  }	

  /** 
   * 画一条由两条连在一起构成的随机正弦函数曲线作干扰线(你可以改成更帅的曲线函数) 
   *      
   *      高中的数学公式咋都忘了涅，写出来
   *		正弦型函数解析式：y=Asin(ωx+φ)+b
   *      各常数值对函数图像的影响：
   *        A：决定峰值（即纵向拉伸压缩的倍数）
   *        b：表示波形在Y轴的位置关系或纵向移动距离（上加下减）
   *        φ：决定波形与X轴位置关系或横向移动距离（左加右减）
   *        ω：决定周期（最小正周期T=2π/∣ω∣）
   *
   */
  private function _writeCurve() {
    $px = $py = 0;
    
    // 曲线前部分
    $A = mt_rand(1, $this->imageH/2);                  // 振幅
    $b = mt_rand(-$this->imageH/4, $this->imageH/4);   // Y轴方向偏移量
    $f = mt_rand(-$this->imageH/4, $this->imageH/4);   // X轴方向偏移量
    $T = mt_rand($this->imageH, $this->imageW*2);  // 周期
    $w = (2* M_PI)/$T;
                    
    $px1 = 0;  // 曲线横坐标起始位置
    $px2 = mt_rand($this->imageW/2, $this->imageW * 0.8);  // 曲线横坐标结束位置

    for ($px=$px1; $px<=$px2; $px = $px + 1) {
        if ($w!=0) {
            $py = $A * sin($w*$px + $f)+ $b + $this->imageH/2;  // y = Asin(ωx+φ) + b
            $i = (int) ($this->fontSize/5);
            while ($i > 0) {	
                imagesetpixel($this->_image, $px + $i , $py + $i, $this->_color);  // 这里(while)循环画像素点比imagettftext和imagestring用字体大小一次画出（不用这while循环）性能要好很多				
                $i--;
            }
        }
    }
    
    // 曲线后部分
    $A = mt_rand(1, $this->imageH/2);                  // 振幅		
    $f = mt_rand(-$this->imageH/4, $this->imageH/4);   // X轴方向偏移量
    $T = mt_rand($this->imageH, $this->imageW*2);  // 周期
    $w = (2* M_PI)/$T;		
    $b = $py - $A * sin($w*$px + $f) - $this->imageH/2;
    $px1 = $px2;
    $px2 = $this->imageW;

    for ($px=$px1; $px<=$px2; $px=$px+ 1) {
        if ($w!=0) {
            $py = $A * sin($w*$px + $f)+ $b + $this->imageH/2;  // y = Asin(ωx+φ) + b
            $i = (int) ($this->fontSize/5);
            while ($i > 0) {			
                imagesetpixel($this->_image, $px + $i, $py + $i, $this->_color);	
                $i--;
            }
        }
    }
  } 

  /* 加密验证码 */
  private function authcode($str){
    $key = substr(md5($this->seKey), 5, 8);
    $str = substr(md5($str), 8, 10);
    return md5($key . $str);
  }  

  /**
   * 绘制背景图片
   * 注：如果验证码输出图片比较大，将占用比较多的系统资源
   */
  private function _background() {
      $path = dirname(__FILE__).‘/Verify/bgs/‘;
      $dir = dir($path);

      $bgs = array();		
      while (false !== ($file = $dir->read())) {
          if($file[0] != ‘.‘ && substr($file, -4) == ‘.jpg‘) {
              $bgs[] = $path . $file;
          }
      }
      $dir->close();

      $gb = $bgs[array_rand($bgs)];

      list($width, $height) = @getimagesize($gb);
      // Resample
      $bgImage = @imagecreatefromjpeg($gb);
      @imagecopyresampled($this->_image, $bgImage, 0, 0, 0, 0, $this->imageW, $this->imageH, $width, $height);
      @imagedestroy($bgImage);
  }   
}

<?php
namespace Home\Controller;
use Think\Controller;
use Home\Common\VerifyProcess;

class TestVerifyController extends Controller {

	// 界面
	public function index() {
		$this->display(‘User/verify‘);
	}

	// 验证
	public function check_verify() {
		
		$verify = new VerifyProcess();
    if(!$verify->check($_POST[‘verify‘])) {
        $this->error(‘验证码错误‘);
    }
	}

    // 显示验证码
    public function verify() {
			$verify = new VerifyProcess();
			$verify->entryProcess();
    }	
}

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script src="http://lib.sinaapp.com/js/jquery/1.9.1/jquery-1.9.1.min.js"></script>
</head>
<body>
	<form action="{:U(‘Home/TestVerify/check_verify‘,‘‘,‘‘)}" method="post">
		<table>
			<tr>
				<td>验证码：</td>
				<td><input type="text" name="verify"></td>
				<td>
					<img id="verify" src="{:U(‘Home/TestVerify/verify‘,‘‘,‘‘)}" style="cursor: pointer;" ><a id="refresh" href="javascript:void(0)">更换验证码</a></td>
			</tr>
			<tr>
				<td colspan="2">
					<input type="submit" value="提交">
				</td>
			</tr>
		</table>
	</form>
</body>
<script>
	$(function(){

		$src = $("#verify").attr(‘src‘);

		$("#refresh").click(function(){
			change_verify();
		});		

		$("#verify").click(function(){
			change_verify();
		});

		function change_verify() {
			$(‘#verify‘).attr(‘src‘, $src + ‘?‘ + Math.random());
		}
	});

</script>
</html>