php网页生成验证码实现程序-PHP源码-php.cn

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

复制代码

/**
* 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) – $this->width));
$randy=rand(0,(imagesy($bghanddle) – $this->height));
}
imagecopy($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;$itext);$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

复制代码

/**
* 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 {
$randstr.=substr($chars,rand(0,strlen($chars)),1);
}
return $randstr;
}
?>
php网页生成验证码实现程序

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

/**
* 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     {
        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             {
                $colorRandom = mt_rand(0,sizeof($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         {
            $colorRandom = mt_rand(0,sizeof($colorList)-1);
            imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);

        }
        // 添加干扰线
        for($k = 0; $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();
}

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checkcode.php文件如下

代码如下	复制代码
? 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"]); ?>