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PHP programming must learn verification code every day_php skills
- WBOYOriginal
- 2016-05-16 19:57:491661browse
This article shares the implementation code of PHP image verification code for everyone for your reference. The specific content is as follows
1. Verification code image generation
captcha.php
//1.生成100*30大小的图片,默认为黑色
$image = imagecreatetruecolor(100,30);
//创建白色底图
$bgcolor = imagecolorallocate($image,255,255,255);
//用白色填充黑色
imagefill ($image,0,0,$bgcolor);
//2.随机显示数字或字母
$captch_code = "";
for($i=0;$i<4;$i++){
$fontsize=6;
$fontcolor=imagecolorallocate($image,rand(0,120),rand(0,120),rand(0,120));
$data = "abcdefghijkmnpqrstuvwxy3456789";
$fontcontent =substr($data,rand(0,strlen($data)),1);
$captch_code .=$fontcontent;
$x = ($i*100/4)+rand(5,10);
$y = rand(5,10);
imagestring($image, $fontsize, $x, $y, $fontcontent,$fontcolor);
}
$_SESSION["authcode"] = $captch_code;
//3.增加干扰
//干扰点
for($i=0;$i<100;$i++){
$pointcolor=imagecolorallocate($image,rand(50,200),rand(50,200),rand(50,200));
imagesetpixel($image,rand(1,99),rand(1,29),$pointcolor);
}
//干扰线
for($i=0;$i<2;$i++){
$linecolor=imagecolorallocate($image,rand(80,220),rand(80,220),rand(80,220));
imageline($image,rand(1,99),rand(1,29),rand(1,99),rand(1,29),$linecolor);
}
header("content-type:image/png");
imagepng($image);
2. The page implements the verification code function
form.php
<?php
if(isset($_POST["authcode"])){
session_start();
if(strtolower($_POST["authcode"])==$_SESSION["authcode"]){
echo "OK";
}else{
echo "NO";
}
}
?>
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<form action="form.php" method="post">
<p>验证码图片: <img id="img" border="1" src="captcha.php?r=<?php echo rand()?>" alt="">
<a href="javascript:void(0)" onclick="document.getElementById('img').src='captcha.php?r'+Math.random() ">换一个</a>
</p>
<p><input type="text" name="authcode"></p>
<p><input type="submit" value="提交"></p>
</form>
</body>
</html>
The above is the entire content of this article to help you easily implement PHP image verification code.
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