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How to implement arithmetic verification code in php
- 不言Original
- 2018-07-05 15:04:562439browse
This article mainly introduces the method of implementing arithmetic verification code in PHP. It has certain reference value. Now I share it with you. Friends in need can refer to it.
I have recently learned PHP. I also practiced the implementation of image functions and verification codes. Following the teacher’s advice, I wrote an arithmetic verification code function. It was the first time I completed a small exercise independently. I felt quite happy. However, I also knew my own limitations. , so I wrote it out specifically, hoping that the experts from all walks of life can give me some guidance and expand my horizons more
The php code is as follows: Implement the function of the verification code
<?php/**
* @param int $width 宽度,默认为120
* @param int $height 高度,默认为50
* @param int $fontSize 字体的大小
* @return 图片资源
*/function arithmeticCode($width=120,$height=50,$fontSize=20){
//开启session
session_start(); //创建画布
$img = imagecreatetruecolor($width,$height); //分配颜色
$color = imagecolorallocate($img,255,255,255); //填充颜色
imagefill($img,0,0,$color); //干扰点
for ($i = 0;$i < 500;$i++){ $pixColor = imagecolorallocate($img,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200));
imagesetpixel($img,mt_rand(0,$width),mt_rand(0,$height),$pixColor);
} //干扰线
for ($i = 0;$i < 4;$i++){ $lineColor = imagecolorallocate($img,mt_rand(0,120),mt_rand(0,120),mt_rand(0,120));
imageline($img,mt_rand(0,$width),mt_rand(0,$height),mt_rand(0,$width),mt_rand(0,$height),$lineColor);
} //定义一个数组存放运算符号
$arr = ['+','-','*']; //计算数组的长度
$len = count($arr); //定义一个1到20的数组
$num = range(1,20); $numLen = count($num); //定义一个空数组来存放随机取得的验证码
$code = []; for ($i = 0;$i < $len;$i++) { if ($i == 1) { $code[] = $arr[mt_rand(0,$len-1)];
}else { $code[] = $num[mt_rand(0,$numLen-1)];
}
} $str = implode($code);//将数组转为字符串
$textColor = imagecolorallocate($img,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200)); $fontAngle = 0; $x = ($width - $fontSize*3)/2; $y = ($height - $fontSize) / 2 + $fontSize;
imagettftext($img,$fontSize,$fontAngle,$x,$y,$textColor,"./img/msyh.ttc",$str); $res = getRes($code); //将函数存放在session中
$_SESSION['res'] = $res; //输出图片
header("content-type:image/png");
imagepng($img);
}/**
* @param $arr 一个包含运算符号的数组
* @return 返回一个运算结果
*/function getRes($arr) {
$sum = 0; //判断数组元素下标为1的运算符号是什么
switch ($arr[1]){ case '+': $sum = $arr[0] + $arr[2]; break; case '-': $sum = $arr[0] - $arr[2]; break; case '*': $sum = $arr[0] * $arr[2]; break;
} return $sum;
}//调用函数arithmeticCode(100,40,18);Part of the code of html
<!doctype html><html lang="en"><head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
img { position: relative; top: 20px; }
</style></head><body><form action="test.php">
验证码 <input type="text" name="code">
<img src="./demo5.php" alt="点击刷新">
<br>
<button>提交</button></form></body></html><script>
//实现点击图片刷新验证码的功能
var img = document.querySelector("img");
img.onclick = function () {
this.src = this.src+"?m="+Math.random();
}</script>Test of test.php
<?phpsession_start();$res = $_SESSION['res'];$value = $_GET['code'];if ($res == $value) { echo "test success";
}else{ echo "test fail";
}The above is the composition of my code.
I hope everyone can The great god is willing to teach you [Looking forward to the face]
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