一个经典的PHP验证码类分享
这篇文章主要介绍了一个经典的PHP验证码类分享,本文不仅提供了类代码,还提供了使用例子及表单中使用的方法,需要的朋友可以参考下
我们通过PHP的GD库图像处理内容，设计一个验证码类Vcode。将该类声明在文件vcode.class.php中，并通过面向对象的特性将一些实现的细节封装在该类中。只要在创建对象时，为构造方法提供三个参数，包括创建验证码图片的宽度、高度及验证码字母个数，就可以成功创建一个验证码类的对象。该类的声明代码如下所示：
在上面的脚本中，虽然声明验证码类Vcode的代码比较多，但细节都被封装在类中，只要直接输出对象，就可以向客户端浏览器中输出幅图片，并可以在浏览器表单中使用。另外本类自动获取验证码图片中的字符串，促成在服务的$_SESSION["code"]中。在提交表单时，只有用户在表单中输入验证码图片上显示的文字，并和服务器中保留的验证码字符串完全相同时，表单才可以提交成功。（注意：验证码在服务器端在$_SESSION["code"]中，所以必须开启session会话才能使用该类，）
在下面的脚本code.php中，使用session_start()开启用户会话控制，然后包含验证码类Vcode所在文件vcode.class.php,创建该类对象并直接输出。就可以将随机生成的验证码图片发送出去，同时会自动将这个验证码字符串保存在服务器中一份。代码如下所示：
<?php
class Vcode {
private $width; //宽
private $height; //高
private $num; //数量
private $code; //验证码
private $img; //图像的资源 //构造方法， 三个参数
function __construct($width=80, $height=20, $num=4)
{
$this->width = $width;
$this->height = $height;
$this->num = $num;
$this->code = $this->createcode();
//调用自己的方法
}
//获取字符的验证码，， 用于保存在服务器中
function getcode() {
return $this->code;
}
//输出图像
function outimg() {
//创建背景 (颜色， 大小， 边框)
$this->createback();
//画字 (大小， 字体颜色)
$this->outstring();
//干扰元素(点， 线条)
$this->setdisturbcolor();
//输出图像
$this->printimg(); }
//创建背景
private function createback() {
//创建资源
$this->img = imagecreatetruecolor($this->width, $this->height);
//设置随机的背景颜色
$bgcolor = imagecolorallocate($this->img, rand(225, 255), rand(225, 255), rand(225, 255));
//设置背景填充
imagefill($this->img, 0, 0, $bgcolor);
//画边框
$bordercolor = imagecolorallocate($this->img, 0, 0, 0);
imagerectangle($this->img, 0, 0, $this->width-1, $this->height-1, $bordercolor); }
//画字
private function outstring() {
for($i=0; $i<$this->num; $i++) {
$color= imagecolorallocate($this->img, rand(0, 128), rand(0, 128), rand(0, 128));
$fontsize=rand(3,5); //字体大小
$x = 3+($this->width/$this->num)*$i; //水平位置
$y = rand(0, imagefontheight($fontsize)-3); //画出每个字符
imagechar($this->img, $fontsize, $x, $y, $this->code{$i}, $color); } }
//设置干扰元素
private function setdisturbcolor() {
//加上点数
for($i=0; $i<100; $i++) {
$color= imagecolorallocate($this->img, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($this->img, rand(1, $this->width-2), rand(1, $this->height-2), $color); }
//加线条
for($i=0; $i<10; $i++) { $color= imagecolorallocate($this->img, rand(0, 255), rand(0, 128), rand(0, 255));
imagearc($this->img,rand(-10, $this->width+10), rand(-10, $this->height+10), rand(30, 300), rand(30, 300),
55,44, $color); } }
//输出图像
private function printimg() {
if (imagetypes() & IMG_GIF) {
header("Content-type: image/gif");
imagegif($this->img); }
elseif (function_exists("imagejpeg"))
{ header("Content-type: image/jpeg");
imagegif($this->img); } elseif (imagetypes() & IMG_PNG)
{ header("Content-type: image/png");
imagegif($this->img); } else { die("No image support in this PHP server"); } }
//生成验证码字符串
private function createcode()
{
$codes = "3456789abcdefghijkmnpqrstuvwxyABCDEFGHIJKLMNPQRSTUVWXY";
$code = "";
for($i=0; $i < $this->num; $i++)
{
$code .=$codes{rand(0, strlen($codes)-1)}; }
return $code;
}
//用于自动销毁图像资源
function __destruct() {
imagedestroy($this->img);
}
}在下面的脚本code.php中，使用session_start()开启用户会话控制，然后包含验证码类Vcode所在文件vcode.class.php,创建该类对象并直接输出。就可以将随机生成的验证码图片发送出去，同时会自动将这个验证码字符串保存在服务器中一份。代码如下所示：
<?php //开启 session session_start(); include "vcode.class.php"; //构造方法 $vcode = new Vcode(80, 30, 4); //将验证码放到服务器自己的空间保存一份 $_SESSION['code'] = $vcode->getcode(); //将验证码图片输出 $vcode->outimg(); ?>
表单代码如下所示：
<?php
session_start();
if(isset($_POST['dosubmit'])) {
if(strtoupper($_SESSION['code']) == strtoupper($_POST['code']) ) {
echo "输入成功!<br>"; }else{ echo "输入不对!<br>"; } }
?>
<body>
<form action="reg.php" method="post"> username: <input type="text">
<br> password: <input type="password">
<br> code: <input type="text"
onkeyup="if(this.value!=this.value.toUpperCase()) this.value=this.value.toUpperCase()" size="6">
<img src="code.php" />
<br>
<input type="submit" value="登 录">
<br>
</form>
</body>
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