运行结果：
<!--vcode.class.php-->
<?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}, $color);
}
}
//设置干扰元素
private function setdisturbcolor() {
//加上点数,100个点
for($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), $color);
}
//加线条,10条线
for($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);
}
}
<!--reg.php-->
<?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" name="username"> <br>
password: <input type="password" name="password"> <br>
code: <input type="text" onkeyup="if(this.value!=this.value.toUpperCase()) this.value=this.value.toUpperCase()" size="6" name="code">
<img src="code.php" onclick="this.src=‘code.php?‘+Math.random()" /> <br>
<input type="submit" name="dosubmit" value="登 录"> <br>
</form>
</body>
<!--code.php内容-->
<?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();