How to generate image verification code in PHP,
This article shares the method of generating image verification code in PHP for your reference. The specific content is as follows
First, randomly select a fixed number of characters from the specified character set, draw them on the canvas in an irregular way, then add some interference points and interference elements appropriately, and finally output the picture, and a brand new verification code will be Done.
The front-end code is as follows:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<title>This is a test!</title>
<link rel="stylesheet" type="text/css" href="css/bootstrap.min.css">
</head>
<body>
<form name="form">
<input type="text" placeholder="賬號"/><br/>
<input type="password" placeholder="密碼"/><br/>
<input type="text" placeholder="驗證碼"/>
<img id="verImg" src="libs/verification.php"/>
<a href="#" class="change" onclick="changeVer()">點擊刷新</a><br/>
<input type="submit" value="登錄"/>
</form>
<script type="text/javascript">
//刷新驗證碼
function changeVer(){
document.getElementById("verImg").src="libs/verification.php?tmp="+Math.random();
}
</script>
</body>
</html>
The code for the php script file verification code is as follows:
<?php
session_start();
//開啟session記錄驗證碼數(shù)據(jù)
vCode(4, 15);//設置驗證碼的字符個數(shù)和圖片基礎寬度
//vCode 字符數(shù)目，字體大小，圖片寬度、高度
function vCode($num = 4, $size = 20, $width = 0, $height = 0) {
!$width && $width = $num * $size * 4 / 5 + 15;
!$height && $height = $size + 10;
//設置驗證碼字符集合
$str = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVW";
//保存獲取的驗證碼
$code = '';
//隨機選取字符
for ($i = 0; $i < $num; $i++) {
$code .= $str[mt_rand(0, strlen($str)-1)];
}
//創(chuàng)建驗證碼畫布
$im = imagecreatetruecolor($width, $height);
//背景色
$back_color = imagecolorallocate($im, mt_rand(0,100),mt_rand(0,100), mt_rand(0,100));
//文本色
$text_color = imagecolorallocate($im, mt_rand(100, 255), mt_rand(100, 255), mt_rand(100, 255));
imagefilledrectangle($im, 0, 0, $width, $height, $back_color);
// 畫干擾線
for($i = 0;$i < 5;$i++) {
$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));
imagearc($im, mt_rand(- $width, $width), mt_rand(- $height, $height), mt_rand(30, $width * 2), mt_rand(20, $height * 2), mt_rand(0, 360), mt_rand(0, 360), $font_color);
}
// 畫干擾點
for($i = 0;$i < 50;$i++) {
$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));
imagesetpixel($im, mt_rand(0, $width), mt_rand(0, $height), $font_color);
}
//隨機旋轉(zhuǎn)角度數(shù)組
$array=array(5,4,3,2,1,0,-1,-2,-3,-4,-5);
// 輸出驗證碼
// imagefttext(image, size, angle, x, y, color, fontfile, text)
@imagefttext($im, $size , array_rand($array), 12, $size + 6, $text_color, 'c:\WINDOWS\Fonts\simsun.ttc', $code);
$_SESSION["VerifyCode"]=$code;
//no-cache在每次請求時都會訪問服務器
//max-age在請求1s后再次請求會再次訪問服務器，must-revalidate則第一發(fā)送請求會訪問服務器，之后不會再訪問服務器
// header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
header("Cache-Control: no-cache");
header("Content-type: image/png;charset=gb2312");
//將圖片轉(zhuǎn)化為png格式
imagepng($im);
imagedestroy($im);
}
?>
Rendering:
The above is the entire content of this article. I hope it will be helpful for everyone to learn PHP programming and learn to write PHP image verification codes
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