session_start();
class authnum {
//图片对象、宽度、高度、验证码长度
private $im;
private $im_width;
private $im_height;
private $len;
//随机字符串、y轴坐标值、随机颜色
private $randnum;
private $y;
private $randcolor;
//背景色的红绿蓝，默认是浅灰色
public $red=238;
public $green=238;
public $blue=238;
/**
* 可选设置：验证码类型、干扰点、干扰线、y轴随机
* 设为 false 表示不启用
**/
//默认是大小写数字混合型，1 2 3 分别表示 小写、大写、数字型
public $ext_num_type='';
public $ext_pixel = false; //干扰点
public $ext_line = false; //干扰线
public $ext_rand_y= true; //y轴随机
function __construct ($len=4,$im_width='',$im_height=25) {
// 验证码长度、图片宽度、高度是实例化类时必需的数据
$this->len = $len; $im_width = $len * 15;
$this->im_width = $im_width;
$this->im_height= $im_height;
$this->im = imagecreate($im_width,$im_height);
}
// 设置图片背景颜色，默认是浅灰色背景
function set_bgcolor () {
imagecolorallocate($this->im,$this->red,$this->green,$this->blue);
}
// 获得任意位数的随机码
function get_randnum () {
$an1 = 'abcdefghijklmnopqrstuvwxyz';
$an2 = 'abcdefghijklmnopqrstuvwxyz';
$an3 = '0123456789';
if ($this->ext_num_type == '') $str = $an1.$an2.$an3;
if ($this->ext_num_type == 1) $str = $an1;
if ($this->ext_num_type == 2) $str = $an2;
if ($this->ext_num_type == 3) $str = $an3;
for ($i = 0; $i < $this->len; $i++) {
$start = rand(1,strlen($str) - 1);
$randnum .= substr($str,$start,1);
}
$this->randnum = $randnum;
$_session[an] = $this->randnum;
}
// 获得验证码图片y轴
function get_y () {
if ($this->ext_rand_y) $this->y = rand(5, $this->im_height/5);
else $this->y = $this->im_height / 4 ;
}
// 获得随机色
function get_randcolor () {
$this->randcolor = imagecolorallocate($this->im,rand(0,100),rand(0,150),rand(0,200));
}
// 添加干扰点
function set_ext_pixel () {
if ($this->ext_pixel) {
for($i = 0; $i < 100; $i++){
$this->get_randcolor();
imagesetpixel($this->im, rand()%100, rand()%100, $this->randcolor);
}
}
}
// 添加干扰线
function set_ext_line () {
if ($this->ext_line) {
for($j = 0; $j < 2; $j++){
$rand_x = rand(2, $this->im_width);
$rand_y = rand(2, $this->im_height);
$rand_x2 = rand(2, $this->im_width);
$rand_y2 = rand(2, $this->im_height);
$this->get_randcolor();
imageline($this->im, $rand_x, $rand_y, $rand_x2, $rand_y2, $this->randcolor);
}
}
}
/**创建验证码图像：
* 建立画布（__construct函数）
* 设置画布背景（$this->set_bgcolor();）
* 获取随机字符串（$this->get_randnum ();）
* 文字写到图片上（imagestring函数）
* 添加干扰点/线（$this->set_ext_line(); $this->set_ext_pixel();）
* 输出图片
**/
function create () {
$this->set_bgcolor();
$this->get_randnum ();
for($i = 0; $i < $this->len; $i++){
$font = rand(4,6);
$x = $i/$this->len * $this->im_width + rand(1, $this->len);
$this->get_y();
$this->get_randcolor();
imagestring($this->im, $font, $x, $this->y, substr($this->randnum, $i ,1), $this->randcolor);
}
$this->set_ext_line();
$this->set_ext_pixel();
header("content-type:image/png");
imagepng($this->im);
imagedestroy($this->im); //释放图像资源
}}//end class
/**使用验证码类的方法：
* $an = new authnum(验证码长度,图片宽度,图片高度);
* 实例化时不带参数则默认是四位的60*25尺寸的常规验证码图片
* 表单页面检测验证码的方法，对比 $_session[an] 是否等于 $_post[验证码文本框id]
* 可选配置：
* 1.验证码类型：$an->ext_num_type=1; 值为1是小写类型，2是大写类型，3是数字类型
* 2.干扰点：$an->ext_pixel = false; 值为false表示不添加干扰点
* 3.干扰线：$an->ext_line = false; 值为false表示不添加干扰线
* 4.y轴随机：$an->ext_rand_y = false; 值为false表示不支持图片y轴随机
* 5.图片背景：改变 $red $green $blue 三个成员变量的值即可
**/
$an = new authnum();
$an->ext_num_type='';
$an->ext_pixel = true; //干扰点
$an->ext_line = false; //干扰线
$an->ext_rand_y= true; //y轴随机
$an->green = 238;
$an->create();
?>
好下面来看一款验证码调用实例
例子demo:
以下为引用的内容：
<!doctype html public "-//w3c//dtd xhtml 1.0 transitional//en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=gb2312" />
<title>hi.baidu.com/ji_haiyang</title>
</head><body>
<form action ="demo1.php教程" method="post" name="form1">
<input name ="test" type="text" value="1234" />
<div onclick='this.innerhtml="<img src=vcode.php?r="+math.random()+"></img>"'>
<img src="vcode.php"></img>
</div>
<input name ="test2" type="text" value="1" />
<input name ="submit" type="submit" value="submit" />
</form></body>
</html>
例子demo1:
<?php
session_start();
$test = $_post['test'];
$test = trim($test);
$submit = $_post['submit'];
if($test==$_session['vcode']){
echo 'true,输入验证码正确';
} else {
echo 'false，输入验证码错误';
}?>
调用文件vcode.php: 以下为引用的内容：
<?php
/**
* 默认验证码session为vcode.即:$_session['vcode'];
* 注意在给变量符值时不要把变量的名子和session冲突
* 注:在验证时不分大小写
*/
include("inc_vcode_class.php");
$v = new vcode;
//$config['width'] = 50; //验证码宽
//$config['height'] = 20; //验证码高
//$config['vcode'] = "vcode"; //检查验证码时用的session
//$config['type'] = "default"; //验证码展示的类型default:大写字母,string:小写字母,int:数字 php程序员站
//$config['length'] = 4; //验证码长度
//$config['interfere']= 10; //干扰线强度,范围为1-30,0或空为不起用干扰线
//$v->init($config); //配置
$v->create();
?>验证码类inc_vcode_class.php: www~phperz~com 以下为引用的内容：
<?php
/**
* 验证码类
* 注:需要gd库支持
*/
session_start();
class vcode{
private $config;
private $im;
private $str;function __construct(){
$this->config['width'] = 50;
$this->config['height'] = 20;
$this->config['vcode'] = "vcode";
$this->config['type'] = "default";
$this->config['length'] = 4;
$this->config['interfere'] = 10;$this->str['default'] = "abcdefghijklmnopqrstuvwxyz";
$this->str['string'] = "abcdefghijklmnopqrstuvwxyz";
$this->str['int'] = "0123456789";
}//配置
public function init($config=array()){
if (!empty($config) && is_array($config)){
foreach($config as $key=>$value){
$this->config[$key] = $value;
}
}
}//输出验证码
public function create(){
if (!function_exists("imagecreate")){
return false;
}
$this->create_do();
}//创建
private function create_do(){
$this->im = imagecreate($this->config['width'],$this->config['height']); php程序员之家
//设置背景为白色
imagecolorallocate($this->im, 255, 255, 255);//为此背景加个边框
$bordercolor= imagecolorallocate($this->im,37,37,37);
imagerectangle($this->im,0,0,$this->config['width']-1,$this->config['height']-1,$bordercolor);//生成验证码
$this->create_str();
$vcode = $_session[$this->config['vcode']];//输入文字
$fontcolor = imagecolorallocate($this->im,46,46,46);
for($i=0;$i<$this->config['length'];$i++){
imagestring($this->im,5,$i*10+6,rand(2,5),$vcode[$i],$fontcolor);
}//加入干扰线
$interfere = $this->config['interfere'];
$interfere = $interfere>30?"30":$interfere; php程序员站
if (!empty($interfere) && $interfere>1){
for($i=1;$i<$interfere;$i++){
$linecolor = imagecolorallocate($this->im,rand(0,255),rand(0,255),rand(0,255));
$x = rand(1,$this->config['width']);
$y = rand(1,$this->config['height']);
$x2 = rand($x-10,$x+10);
$y2 = rand($y-10,$y+10);
imageline($this->im,$x,$y,$x2,$y2,$linecolor);
}
}header("pragma:no-cachern");
header("cache-control:no-cachern");
header("expires:0rn");
header("content-type:image/jpegrn");
imagejpeg($this->im);
imagedestroy($this->im);
exit;
}//得到验证码
private function create_str(){
if ($this->config['type']=="int"){
for($i=1;$i<=$this->config['length'];$i++){
$vcode .= rand(0,9);
}
$_session[$this->config['vcode']] = $vcode;
return true;
}
$len = strlen($this->str[$this->config['type']]);
if (!$len){
$this->config['type'] = "default";
$this->create_str();
}
for($i=1;$i<=$this->config['length'];$i++){
$offset = rand(0,$len-1);
$vcode .= substr($this->str[$this->config['type']],$offset,1);
}
$_session[$this->config['vcode']] = $vcode;
return true;
}
}