當使用ajax和php提交表單提交時驗證captcha

如何驗證用戶是否使用ajax輸入了正確的驗證碼？並且如果$_POST['captchainput'] != $_SESSION['code']阻止提交表單。當使用ajax和php提交表單提交時驗證captcha

這是標記

<form action="captchaccept.php" method="POST" name="maincontact"> <input type="text" placeholder="Please enter the code" autocomplete="off" id="captchainput" name="captchainput"> <img src="captcha.php" id="captchaimage"> </form>

captcha.php

session_start(); 

$image_width = 135; 
$image_height = 30; 
$characters_on_image = 8; 
$font = 'captchafont/acmesa.ttf'; 

$possible_letters = '23456789abcdfghjkmnpqrstvwxyz'; 
$random_dots = 10; 
$random_lines = 30; 
$captcha_text_color="0x142864"; 
$captcha_noice_color = "0x142864"; 

$code = ''; 

$i = 0; 
while ($i < $characters_on_image) { 
    $code .= substr($possible_letters, mt_rand(0, strlen($possible_letters)-1), 1); 
    $i++; 
} 

$_SESSION['code'] = $code; 

$font_size = 14; 
$image = @imagecreate($image_width, $image_height); 

$background_color = imagecolorallocate($image, 255, 255, 255); 

$arr_text_color = hexrgb($captcha_text_color); 
$text_color = imagecolorallocate($image, $arr_text_color['red'], 
$arr_text_color['green'], $arr_text_color['blue']); 

$arr_noice_color = hexrgb($captcha_noice_color); 
$image_noise_color = imagecolorallocate($image, $arr_noice_color['red'], 
$arr_noice_color['green'], $arr_noice_color['blue']); 

for($i=0; $i<$random_dots; $i++) { 
    imagefilledellipse($image, mt_rand(0,$image_width), 
    mt_rand(0,$image_height), 2, 3, $image_noise_color); 
} 

$textbox = imagettfbbox($font_size, 0, $font, $_SESSION['code']); 
$x = ($image_width - $textbox[4])/2; 
$y = ($image_height - $textbox[5])/2; 
imagettftext($image, $font_size, 0, $x, $y, $text_color, $font , $_SESSION['code']); 

header('Content-Type: image/jpeg'); 
imagejpeg($image); 
imagedestroy($image); 

function hexrgb ($hexstr) { 
    $int = hexdec($hexstr); 

    return array("red" => 0xFF & ($int >> 0x10), 
    "green" => 0xFF & ($int >> 0x8), 
    "blue" => 0xFF & $int); 
}`

captchaaccept.php

` 在session_start（）;

if(isset($_SESSION['code'])) { 
    if(empty($_POST['captchainput']) === false) { 
     if($_SESSION['code'] === $_POST['captchainput']) { 
         echo 'ok'; 
        } 
      } 
    }`

有人可以教我如何使用Ajax驗證這個驗證碼？或只是告訴我一個例子，在此先感謝:)

來源

2013-12-11 peace

你張貼在這裏什麼是工作的罰款？ –

這是一個關於AJAX，PHP，Captchas的教程http://webcheatsheet.com/php/create_captcha_protection.php – zer02

是它的工作正常，但我想要的是通過使用ajax它會自動驗證，如果$ _POST和$ _SESSION是用戶提交表單後相同，如果不相等，則會阻止表單提交併顯示錯誤消息 – peace

使用jQuery你可以做這樣的：

(function($) { 
    $('#captchainput').on('submit', function(e) { 
     // Prevent the browser submitting the form 
     e.preventDefault(); 

     // Put the form in variable form 
     var form = $(this); 

     // Do a AJAX post with the form data and check the response 
     $.post(form.attr('action'), form.serialize(), function(data) { 
      if(data === 'ok') { 
       // Captcha passed! 
      } else { 
       // Captcha failed! 
      } 
     }); 
    }); 
})(jQuery);

而且在你的代碼;
<form action="captchaccept.php" ...應該
<form action="captchaaccept.php" ...我認爲;-)

來源

2013-12-11 10:54:09 Sander

試試這個也...

var posted_captcha = $("#captchainput").val(); 
$.ajax({ 
      url : 'captchaaccept.php', 
      data : 'captchainput=' + posted_captcha, 
      type : 'post', 
      success: function (res) { 
      if(res=='ok'){ 
       alert('Validation pass'); 
      }else{ 
       alert('Validation fail'); 
      } 
      } 
     });

來源

2013-12-11 10:57:20

當使用ajax和php提交表單提交時驗證captcha

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