Verification code for PHP development
Many websites will have a verification code when logging in. Below we will introduce how to implement the verification code function.
There is this section in the code of the previous login page:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"> <meta name="format-detection" content="telephone=no" /> <title>登录页面实例展示</title> <link rel="stylesheet" type="text/css" href="/phpMyAdmin/login.css"/> </head> <body> <p> <span> <input type="text" name="code" id="code" class="pf_ipt_verify w230" placeholder="验证码" autocomplete="off" tabindex="3"/> <img src="/phpMyAdmin/code.php" onClick="this.src='/phpMyAdmin/code.php?nocache='+Math.random()" style="cursor:hand"> </span> </p> </body> </html>
This is the picture of the verification code we see on the page. By giving the verification code image a click event, you can click the image once and change different numbers.
In addition, how the verification code is generated is the following code:
<?php
session_start();
Header("Content-type:image/PNG");
$im = imagecreate(150,45);
$back = imagecolorallocate($im, 245, 245, 245);
imagefill($im, 0,0, $back);
$vcodes = "";
for($i = 0; $i < 4; $i++){
$font = imagecolorallocate($im, rand(100, 255), rand(0, 100), rand(100, 255));
$authnum = rand(0, 9);
$vcodes .= $authnum;
imagestring($im, 5, 50 + $i * 10, 20, $authnum, $font);
}
$_SESSION['VCODE'] = $vcodes;
for($i=0;$i<200;$i++) {
$randcolor = imagecolorallocate($im, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($im, rand()%150, rand()%150, $randcolor); //
}
imagepng($im);
imagedestroy($im);
?>This is the background program for code generation.
Judge the code in the login back-end code. One is to judge whether there is input, and the other is to judge whether the input is correct. The code is as follows:
if(!$_POST['code']){
echo('验证码不能为空');
return;
}else if($_POST['code']!=$_SESSION['VCODE']){
echo('验证码不正确');
return;
}
new file
<?php
session_start();
Header("Content-type:image/PNG");
$im = imagecreate(150,45);
$back = imagecolorallocate($im, 245, 245, 245);
imagefill($im, 0,0, $back);
$vcodes = "";
for($i = 0; $i < 4; $i++){
$font = imagecolorallocate($im, rand(100, 255), rand(0, 100), rand(100, 255));
$authnum = rand(0, 9);
$vcodes .= $authnum;
imagestring($im, 5, 50 + $i * 10, 20, $authnum, $font);
}
$_SESSION['VCODE'] = $vcodes;
for($i=0;$i<200;$i++) {
$randcolor = imagecolorallocate($im, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($im, rand()%150, rand()%150, $randcolor); //
}
imagepng($im);
imagedestroy($im);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no">
<meta name="format-detection" content="telephone=no" />
<title>登录页面实例展示</title>
<style>
.mar_auto {
margin-right: auto;
margin-left: auto;
}
.re {
position: relative;
}
.mt70 {
margin-top: 70px;
}
.min_h400 {
min-height: 400px;
}
.w432 {
width: 432px;
}
.btn_1 {
display: inline-block;
line-height: 16px;
padding: 15px 0;
margin-bottom: 30px;
border-radius: 3px;
font-family: Microsoft YaHei,SimHei;
background: #03a9f4;
border: 1px solid #0398db;
color: #fff;
font-size: 20px;
text-align: center;
cursor: pointer;
}
.w430 {
width: 430px;
}
.pf_ipt_user, .pf_ipt_pass, .pf_ipt_verify{
height: 20px;
line-height: 20px;
padding: 13px 20px;
margin-bottom: 30px;
width: 390px;
border: 1px solid #d9d9d9;
border-radius: 3px;
color: #888;
font-size: 16px;
font-family: Microsoft YaHei,SimHei;
}
.w230{
width: 230px;
}
</style>
</head>
<body>
<div>
<img src="http://keep60.com/Project/SxgAdmin/Public/images/platform_login_header_bg.png"/>
</div>
<div class="mt70 w432 mar_auto re min_h400">
<form name="form1" id="form1" method="post" action="login.php">
<p><input type="text" class="pf_ipt_user" placeholder="请输入登录账号" autocomplete="off" name="username" id="_username" tabindex="1"/></p>
<p><input type="password" class="pf_ipt_pass pass_bg_1" placeholder="请输入密码" autocomplete="off" name="password" id="_password" tabindex="2"/></p>
<p>
<span>
<input type="text" name="code" id="code" class="pf_ipt_verify w230" placeholder="验证码" autocomplete="off" tabindex="3"/>
<img src="/phpMyAdmin/code.php" onClick="this.src='/phpMyAdmin/code.php?nocache='+Math.random()" style="cursor:hand">
</span>
</p>
<!--<p><a href="javascript:void(0)" class="btn_1 w430">登录</a></p> -->
<p>
<button class="btn_1 w430">登录</button>
</p>
<p><a href="regedit.html">账号注册</a></p>
</form>
</div>
</body>
</html>
Preview
Clear
- Course Recommendations
- Courseware download
The courseware is not available for download at the moment. The staff is currently organizing it. Please pay more attention to this course in the future~
Students who have watched this course are also learning
Let's briefly talk about starting a business in PHP
Quick introduction to web front-end development
Large-scale practical Tianlongbabu development of Mini version MVC framework imitating the encyclopedia website of embarrassing things
Getting Started with PHP Practical Development: PHP Quick Creation [Small Business Forum]
Login verification and classic message board
Computer network knowledge collection
Quick Start Node.JS Full Version
The front-end course that understands you best: HTML5/CSS3/ES6/NPM/Vue/...[Original]
Write your own PHP MVC framework (40 chapters in depth/big details/must read for newbies to advance)