php+js实现极验，拖动滑块验证码验证表单等

文章来自公众号：PHP自学中心, 链接：http://blog.startphp.cn 作者：磊丰 **转载文章请注明出处

应用场景

现在很多网站，比如淘宝，京东等都改用使用极验拖动验证码实现登录，这种方式比传统的验证码方式有更好的体验，减少用户输入的错误，也同样能起到防盗刷的功能。现在很多极验都是第三方的，也很多都是收费的。今天在这里给大家分享自己用原生php实现的一个极验的代码。用原生php的好处就是以后你要嵌套到什么框架，可以直接用核心代码，改一改就好了。

极验拖动验证实现演示：http://blog.startphp.cn/jiyan/

极验拖动动画图

jiyan.gif

代码文件截图

QQ截图20190715103107.jpg

代码实现

html文件

<!DOCTYPE html>
<html lang="">
<head>
    <meta charset="utf-8">
    <meta http-equiv="x-ua-compatible" content="ie=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>极验滑块拖动验证码-码农社区-web视频分享网</title>
    <script type="text/javascript" src="tn_code.js?v=35"></script>
    <link rel="stylesheet" type="text/css" href="style.css?v=27" />
<style type="text/css"></style>
</head>
<body style="text-align:center;">
<div class="tncode" style="text-align: center;margin: 100px auto;"></div>
<script type="text/javascript">
$TN.onsuccess(function(){
//验证通过
});
</script>

php文件：check.php

<?php
require_once dirname(__FILE__).'/TnCode.class.php';
$tn  = new TnCode();
if($tn->check()){
	$_SESSION['tncode_check'] = 'ok';
    echo "ok";
}else{
	$_SESSION['tncode_check'] = 'error';
    echo "error";
}

?>

主要核心文件：TnCode.class.php

<?php
class TnCode
{
    var $im = null;
    var $im_fullbg = null;
    var $im_bg = null;
    var $im_slide = null;
    var $bg_width = 240;
    var $bg_height = 150;
    var $mark_width = 50;
    var $mark_height = 50;
    var $bg_num = 6;
    var $_x = 0;
    var $_y = 0;
    //容错象素 越大体验越好，越小破解难道越高
    var $_fault = 3;
    function __construct(){
        //ini_set('display_errors','On');
        //
        error_reporting(0);
        if(!isset($_SESSION)){
            session_start();
        }
    }
    function make(){
        $this->_init();
        $this->_createSlide();
        $this->_createBg();
        $this->_merge();
        $this->_imgout();
        $this->_destroy();
    }

    function check($offset=''){
        if(!$_SESSION['tncode_r']){
            return false;
        }
        if(!$offset){
            $offset = $_REQUEST['tn_r'];
        }
        $ret = abs($_SESSION['tncode_r']-$offset)<=$this->_fault;
        if($ret){
            unset($_SESSION['tncode_r']);
        }else{
            $_SESSION['tncode_err']++;
            if($_SESSION['tncode_err']>10){//错误10次必须刷新
                unset($_SESSION['tncode_r']);
            }
        }
        return $ret;
    }

    private function _init(){
        $bg = mt_rand(1,$this->bg_num);
        $file_bg = dirname(__FILE__).'/bg/'.$bg.'.png';
        $this->im_fullbg = imagecreatefrompng($file_bg);
        $this->im_bg = imagecreatetruecolor($this->bg_width, $this->bg_height);
        imagecopy($this->im_bg,$this->im_fullbg,0,0,0,0,$this->bg_width, $this->bg_height);
        $this->im_slide = imagecreatetruecolor($this->mark_width, $this->bg_height);
        $_SESSION['tncode_r'] = $this->_x = mt_rand(50,$this->bg_width-$this->mark_width-1);
        $_SESSION['tncode_err'] = 0;
        $this->_y = mt_rand(0,$this->bg_height-$this->mark_height-1);
    }

    private function _destroy(){
        imagedestroy($this->im);
        imagedestroy($this->im_fullbg);
        imagedestroy($this->im_bg);
        imagedestroy($this->im_slide);
    }
    private function _imgout(){
        if(!$_GET['nowebp']&&function_exists('imagewebp')){//优先webp格式，超高压缩率
            $type = 'webp';
            $quality = 40;//图片质量 0-100
        }else{
            $type = 'png';
            $quality = 7;//图片质量 0-9
        }
        header('Content-Type: image/'.$type);
        $func = "image".$type;
        $func($this->im,null,$quality);
    }
    private function _merge(){
        $this->im = imagecreatetruecolor($this->bg_width, $this->bg_height*3);
        imagecopy($this->im, $this->im_bg,0, 0 , 0, 0, $this->bg_width, $this->bg_height);
        imagecopy($this->im, $this->im_slide,0, $this->bg_height , 0, 0, $this->mark_width, $this->bg_height);
        imagecopy($this->im, $this->im_fullbg,0, $this->bg_height*2 , 0, 0, $this->bg_width, $this->bg_height);
        imagecolortransparent($this->im,0);//16777215
    }

    private function _createBg(){
        $file_mark = dirname(__FILE__).'/img/mark.png';
        $im = imagecreatefrompng($file_mark);
        header('Content-Type: image/png');
        //imagealphablending( $im, true);
        imagecolortransparent($im,0);//16777215
        //imagepng($im);exit;
        imagecopy($this->im_bg, $im, $this->_x, $this->_y  , 0  , 0 , $this->mark_width, $this->mark_height);
        imagedestroy($im);
    }

    private function _createSlide(){
        $file_mark = dirname(__FILE__).'/img/mark2.png';
        $img_mark = imagecreatefrompng($file_mark);
        imagecopy($this->im_slide, $this->im_fullbg,0, $this->_y , $this->_x, $this->_y, $this->mark_width, $this->mark_height);
        imagecopy($this->im_slide, $img_mark,0, $this->_y , 0, 0, $this->mark_width, $this->mark_height);
        imagecolortransparent($this->im_slide,0);//16777215
        //header('Content-Type: image/png');
        //imagepng($this->im_slide);exit;
        imagedestroy($img_mark);
    }

}
?>

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链接：http://blog.startphp.cn/thread-165-1-1.html