php 验证码
来源: 慕课网教程
产生一张图片
<?php $image = imagecreatetruecolor(300,200); $white = imagecolorallocate($image, 255,255,255); $black = imagecolorallocate($image, 0, 0, 0); imagefill($image, 0, 0, $white); header(‘content-type: image/png‘); imagepng($image); imagedestroy($image); ?>
<?php $filename = dirname(__FILE__).DIRECTORY_SEPARATOR.‘pic0.jpg‘; $contents = file_get_contents($filename); header(‘content-type: image/jpg‘); echo $contents; ?>
添加数字
<?php
$image = imagecreatetruecolor(300,200);
$white = imagecolorallocate($image, 255,255,255);
$black = imagecolorallocate($image, 0, 0, 0);
imagefill($image, 0, 0, $white);
// 随机数字
for ($i = 0; $i < 4; $i++) {
$fontsize = 6;
$fontcontent = rand(0, 9);
$fontcolor = imagecolorallocate($image, rand(0, 120), rand(0, 120), rand(0, 120));
$x = $i * 100/4 + rand(5, 10);
$y = rand(5, 10);
imagestring($image, $fontsize, $x, $y, $fontcontent, $fontcolor);
}
header(‘content-type: image/png‘);
imagepng($image);
imagedestroy($image);
?>
干扰点和干扰线
for ($i = 0; $i < 150; $i++) {
$pointcolor = imagecolorallocate($image, rand(50, 200), rand(50, 200), rand(50, 200));
imagesetpixel($image, rand(1, 99), rand(1, 29), $pointcolor);
}
for ($i = 0; $i < 4; $i++) {
$linecolor = imagecolorallocate($image, rand(150, 200), rand(150, 200), rand(150, 200));
imageline($image, rand(1, 99), rand(1, 20), rand(1, 99), rand(1, 20), $linecolor);
}
实现字母和数字的验证码
$data = ‘3456789abcdefghjkmnpqrstuvwxy‘; // 去掉 0 和 o, 1 和 l
$len = strlen($data);
for ($i = 0; $i < 4; $i++) {
$fontsize = 8;
$fontcontent = $data[rand(0, $len)];
$fontcolor = imagecolorallocate($image, rand(0, 120), rand(0, 120), rand(0, 120));
$x = $i * 100/4 + rand(5, 10);
$y = rand(5, 10);
imagestring($image, $fontsize, $x, $y, $fontcontent, $fontcolor);
}
验证登陆
verify.php
<?php
session_start();
$image = imagecreatetruecolor(100,30);
$white = imagecolorallocate($image, 255,255,255);
$black = imagecolorallocate($image, 0, 0, 0);
imagefill($image, 0, 0, $white);
$captch_code = ‘‘;
$data = ‘3456789abcdefghjkmnpqrstuvwxy‘;
$len = strlen($data);
for ($i = 0; $i < 4; $i++) {
$fontsize = 8;
$fontcontent = $data[rand(0, $len)];
$captch_code .= $fontcontent;
$fontcolor = imagecolorallocate($image, rand(0, 120), rand(0, 120), rand(0, 120));
$x = $i * 100/4 + rand(5, 10);
$y = rand(5, 10);
imagestring($image, $fontsize, $x, $y, $fontcontent, $fontcolor);
}
$_SESSION[‘authcode‘] = $captch_code;
for ($i = 0; $i < 150; $i++) {
$pointcolor = imagecolorallocate($image, rand(50, 200), rand(50, 200), rand(50, 200));
imagesetpixel($image, rand(1, 99), rand(1, 29), $pointcolor);
}
for ($i = 0; $i < 4; $i++) {
$linecolor = imagecolorallocate($image, rand(150, 200), rand(150, 200), rand(150, 200));
imageline($image, rand(1, 99), rand(1, 20), rand(1, 99), rand(1, 20), $linecolor);
}
header(‘content-type: image/png‘);
imagepng($image);
imagedestroy($image);
?>
form.php
<?php
if (isset($_REQUEST[‘authcode‘])) {
session_start();
if (strtolower($_REQUEST[‘authcode‘]) == $_SESSION[‘authcode‘]) {
echo ‘<font color="#00C"> succees </font>‘;
} else {
echo ‘<font color="#C00"> fail </font>‘;
}
exit();
}
?>
<!DOCTYPE html>
<html lang="en-US">
<head>
<meta charset="utf-8" />
<title>test</title>
</head>
<body>
<form method="post" action="<?php echo $_SERVER[PHP_SELF]; ?>">
<p>验证码图片: <img border="1" src="./verify.php?r=<?php echo rand(); ?>" width="120px"></p>
<p><input type="text" size="10" name="authcode" value=""></p>
<p><input type="submit" value="submit"> </p>
</form>
</body>
</html>
实现刷新
<?php
if (isset($_REQUEST[‘authcode‘])) {
session_start();
if ($_REQUEST[‘authcode‘] == $_SESSION[‘authcode‘]) {
echo ‘<font color="#00C"> succees </font>‘;
} else {
echo ‘<font color="#C00"> fail </font>‘;
}
exit();
}
?>
<!DOCTYPE html>
<html lang="en-US">
<head>
<meta charset="utf-8" />
<title>test</title>
</head>
<body>
<form method="post" action="<?php echo $_SERVER[PHP_SELF]; ?>">
<p>
验证码图片: <img id="captcha_img" border="1" src="./verify.php?r=<?php echo rand(); ?>" width="120px">
<a href="javascript:void(0)" onclick="document.getElementById(‘captcha_img‘).src=‘./verify.php?r=‘+Math.random()">换一个?</a>
</p>
<p><input type="text" size="10" name="authcode" value=""></p>
<p><input type="submit" value="submit"> </p>
</form>
</body>
</html>
图片验证码
form_img.php
<?php
session_start();
$table = array(
‘pic0‘ => ‘dog‘,
‘pic1‘ => ‘cat‘,
‘pic2‘ => ‘fish‘,
‘pic3‘ => ‘bird‘,
);
$index = rand(0, 3);
$value = $table[‘pic‘.$index];
$_SESSION[‘authcode‘] = $value;
$filename = dirname(__FILE__).DIRECTORY_SEPARATOR.‘pic‘.$index.‘.jpg‘;
$contents = file_get_contents($filename);
header(‘content-type: image/jpg‘);
echo $contents;
?>
<?php
if (isset($_REQUEST[‘authcode‘])) {
session_start();
if ($_REQUEST[‘authcode‘] == $_SESSION[‘authcode‘]) {
echo ‘<font color= "#f00";>succeed</font>‘;
} else {
echo ‘<font color= "#00f";>fail</font>‘;
}
exit();
}
?>
<!DOCTYPE html>
<html lang="en-US">
<head>
<meta charset="utf-8" />
<title>test</title>
</head>
<body>
<form methos="post" action="<?php echo $_SERVER[PHP_SELF]; ?>">
<p>图片: <img id="captcha_img" src="./verify_img.php?r=<?php echo rand(); ?>" width="200" height="100">
<a href="javascript:void(0)" onclick="document.getElementById(‘captcha_img‘).src=‘./verify_img.php?r=‘+Math.random()">换一个</a>
</p>
<p><input type="text" name="authcode" size="10"></p>
<input type="submit" value="submit">
</form>
</body>
</html>
verify_img.php
<?php
session_start();
$table = array(
‘pic0‘ => ‘dog‘,
‘pic1‘ => ‘cat‘,
‘pic2‘ => ‘fish‘,
‘pic3‘ => ‘bird‘,
);
$index = rand(0, 3);
$value = $table[‘pic‘.$index];
$_SESSION[‘authcode‘] = $value;
$filename = dirname(__FILE__).DIRECTORY_SEPARATOR.‘pic‘.$index.‘.jpg‘;
$contents = file_get_contents($filename);
header(‘content-type: image/jpg‘);
echo $contents;
?>
时间： 2024-08-08 21:56:24