php网页生成验证码实现程序
首先在表单页面展现之前,生成一副图片,并添加上一些干扰像素或线段,防止OCR程序自动识别,再由PHP程序自动生成随机的待验证的一串数字和字母组合的字符,调用imagettftext()函数画到图片中,并把这串字符保存到Session级变量中.
完整实例:自动检测背景和字体,并随机选取背景图片中的一块范围,随机使用字体,显示验证字符串时随机显示字体大小,字符间距,字符颜色等,代码如下:
<?php
/**
* Class for Validate image
* @author zcs
* @version 1.0-20090828
*/
session_start();
class validimg {
//背景图片目录
var $backgroundpath = 'validbg';
//生成验证码宽度
var $width = '80';
//生成验证码高度
var $height = '25';
//背景
var $background;
//验证文本
var $text = 'abcd';
//字体目录
var $fontpath = 'validbg';
//字体
var $font = 'simhei.ttf';
//字体宽度
var $font_width = '20';
function validimg($text) {
$this->text = $text;
//随机选取一个背景文件
$bgdir = @dir($this->backgroundpath);
while (false !== ($image = $bgdir->read())) {
if ($image != '.' && $image != '..' && $this->checktype($image) != false) {
$backgroundarr[] = $image;
}
}
$bgdir->close();
//随机选取一个字体文件
$fonts = @dir($this->fontpath);
while (false !== ($font = $fonts->read())) {
if ($font != '.' && $font != '..' && $this->checktype($font, 'FONT') != false) {
$fontsarr[] = $font;
}
}
$fonts->close();
$this->font = $fontsarr[array_rand($fontsarr, 1) ];
$this->background = $backgroundarr[array_rand($backgroundarr, 1) ];
$this->output();
}
//创建背景图像handdle
function createbackground() {
switch ($this->checktype($this->background)) {
case 'jpg':
$bghanddle = @imagecreatefromjpeg($this->backgroundpath . '/' . $this->background);
break;
case 'gif':
$bghanddle = @imagecreatefromgif($this->backgroundpath . '/' . $this->background);
break;
case 'png':
$bghanddle = @imagecreatefrompng($this->backgroundpath . '/' . $this->background);
break;
default:
}
return $bghanddle;
}
//检查文件类型
function checktype($image, $type = 'IMAGE') {
$ext = substr($image, strrpos($image, '.') + 1);
if ($type == 'IMAGE') {
if ($ext == 'jpg' || $ext == 'gif' || $ext == 'png') return $ext;
else return false;
} else if ($type == 'FONT') {
if ($ext == 'ttf') return $ext;
else return false;
}
}
//输出
function output() {
header("content-type:image/png;");
//生成图像
$img = @imagecreatetruecolor($this->width, $this->height);
$bghanddle = $this->createbackground();
//从背景图像随机位置载入一块作为背景
if ($bghanddle) {
$randx = rand(0, (imagesx($bghanddle) & ndash;
$this->width));
$randy = rand(0, (imagesy($bghanddle) & ndash;
$this->height));
}
imagecopy($img, $bghanddle, 0, 0, $randx, $randy, $this->width, $this->height);
//随机选择角度 字体大小 坐标输出文字
for ($i = 0; $i < strlen($this->text); $i++) {
$angle = rand(-30, 30);
$fontsize = rand(15, 20);
$x = rand($this->font_width * $i, $this->font_width * $i + 10);
$color = imagecolorallocate($img, rand(0, 255) , rand(0, 255) , rand(0, 255));
imagettftext($img, $fontsize, $angle, $x, 20, $color, $this->fontpath . '/' . $this->font, substr($this->text, $i, 1));
}
imagepng($img);
//释放资源
imagedestroy($img);
imagedestroy($bghanddle);
}
}
new validimg($_SESSION['valid']);
?>测试文件validtest.php,代码如下:
<?php
/**
* 验证码测试
* @author zcs
*/
session_start();
$_SESSION['valid'] = randstr();
echo $_SESSION['valid'];
//随机生成字符串
function randstr($num = 4) {
$chars = 'ABDEFGHJKLMNPQRSTVWXYabdefghijkmnpqrstvwxy23456789';
$randstr = '';
for ($i = 0; $i < $num; $i++) {
$randstr.= substr($chars, rand(0, strlen($chars)) , 1);
}
return $randstr;
}
?><img src="validimg.php" />
生成gif动态验证码,PHP生成GIF动画来实现动态图片验证码，以下是实现过程,ImageCode函数通过GIFEncoder类实现的GIF动画
<?php
/**
* ImageCode 生成GIF图片验证
* @param $string 字符串
* @param $width 宽度
* @param $height 高度
*
*/
function ImageCode($string = '', $width = 75, $height = 25) {
$authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));
$board_width = $width;
$board_height = $height;
// 生成一个32帧的GIF动画
for ($i = 0; $i < 32; $i++) {
ob_start();
$image = imagecreate($board_width, $board_height);
imagecolorallocate($image, 0, 0, 0);
// 设定文字颜色数组
$colorList[] = ImageColorAllocate($image, 15, 73, 210);
$colorList[] = ImageColorAllocate($image, 0, 64, 0);
$colorList[] = ImageColorAllocate($image, 0, 0, 64);
$colorList[] = ImageColorAllocate($image, 0, 128, 128);
$colorList[] = ImageColorAllocate($image, 27, 52, 47);
$colorList[] = ImageColorAllocate($image, 51, 0, 102);
$colorList[] = ImageColorAllocate($image, 0, 0, 145);
$colorList[] = ImageColorAllocate($image, 0, 0, 113);
$colorList[] = ImageColorAllocate($image, 0, 51, 51);
$colorList[] = ImageColorAllocate($image, 158, 180, 35);
$colorList[] = ImageColorAllocate($image, 59, 59, 59);
$colorList[] = ImageColorAllocate($image, 0, 0, 0);
$colorList[] = ImageColorAllocate($image, 1, 128, 180);
$colorList[] = ImageColorAllocate($image, 0, 153, 51);
$colorList[] = ImageColorAllocate($image, 60, 131, 1);
$colorList[] = ImageColorAllocate($image, 0, 0, 0);
$fontcolor = ImageColorAllocate($image, 0, 0, 0);
$gray = ImageColorAllocate($image, 245, 245, 245);
$color = imagecolorallocate($image, 255, 255, 255);
$color2 = imagecolorallocate($image, 255, 0, 0);
imagefill($image, 0, 0, $gray);
$space = 15; // 字符间距
if ($i > 0) // 屏蔽第一帧
{
for ($k = 0; $k < strlen($authstr); $k++) {
$colorRandom = mt_rand(0, sizeof($colorList) - 1);
$float_top = rand(0, 4);
$float_left = rand(0, 3);
imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1) , $colorList[$colorRandom]);
}
}
for ($k = 0; $k < 20; $k++) {
$colorRandom = mt_rand(0, sizeof($colorList) - 1);
imagesetpixel($image, rand() % 70, rand() % 15, $colorList[$colorRandom]);
}
// 添加干扰线
for ($k = 0; $k < 3; $k++) {
$colorRandom = mt_rand(0, sizeof($colorList) - 1);
// $todrawline = rand(0,1);
$todrawline = 1;
if ($todrawline) {
imageline($image, mt_rand(0, $board_width) , mt_rand(0, $board_height) , mt_rand(0, $board_width) , mt_rand(0, $board_height) , $colorList[$colorRandom]);
} else {
$w = mt_rand(0, $board_width);
$h = mt_rand(0, $board_width);
imagearc($image, $board_width - floor($w / 2) , floor($h / 2) , $w, $h, rand(90, 180) , rand(180, 270) , $colorList[$colorRandom]);
}
}
imagegif($image);
imagedestroy($image);
$imagedata[] = ob_get_contents();
ob_clean();
++$i;
}
$gif = new GIFEncoder($imagedata);
Header('Content-type:image/gif');
echo $gif->GetAnimation();
}
?><!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script language="javascript">
function refresh_code()
{
form1.imgcode.src="verifycode.php?a="+Math.random();
}
</script>
</head>
<body>
<form id="form1" name="form1" method="post" action="checkcode.php">
<label for="code">验证码：</label>
<input type="text" name="code" id="textfield" />
<img id="imgcode" src="VerifyCode.php" alt="验证码" />
<a href="javascript：refresh_code()">看不清？换一个</a>
<input type="submit" name="button" id="button" value="提交" />
</form>
</body>
</html>checkcode.php文件如下:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<?php
ini_set('display_errors', 'Off');
session_start();
if ((strtoupper($_POST["code"])) == strtoupper(($_SESSION["VerifyCode"]))) {
print ("验证码正确,");
} else {
print ("验证码错误,");
}
echo "提交的验证码:" . strtoupper($_POST["code"]) . ",正确的验证码：" . strtoupper($_SESSION["VerifyCode"]);本文地址：http://www.phprm.com/develop/fs4054.html
转载随意，但请附上文章地址:-)