Question

求一个php验证码及如何使用的例子?

需要生成一个验证码图片,并让用户输入这个验证码检测一下是否正确.
测试通过+100分.一定要能测试通过啊.

Answer 1

以前项目中的东西
在没有GB库的情况下也可以生成验证码
关键部分做出了注释

<img src="image.php">

<?php
//存为文件 image.php
error_reporting(E_ALL ^ E_NOTICE);
require_once('image.class.php');
$image_model = new Image();
//可以在此处更改属性达到验证码不同大小的图片
$image_model->outputBrowser();
?>

<?php
/*
* \验证码生成类 存为文件image.class.php
* \如果不支持GD库，则采用像素画法
* \详见 http://www.tonyang.com
*/

class Image
{
var $img_height = 20; //图片的长
var $img_width = 68; //图片的宽
var $img_cache = ''; //图像信息缓存
var $check_number = ''; //验证码
var $lenght = 4; //验证码位数
var $is_gd = false;

//'----------以下为不支持GD需要的变量
var $pixels = '';
var $digits = '';
var $lines = '';
var $data = '';
var $chunk = '';
var $crc_table = '';

function Image()
{
session_start();
session_register("check_number");

$this->session = &$_SESSION;
$this->is_gd = function_exists('gd_info') ? true : false;
$this->getCheckNumber();

if( $this->is_gd ):
$this->getFromGD();
else:
$this->getFromCode();
endif;
}

//'----浏览器输出
function outputBrowser()
{
if( $this->is_gd )
{
Header("Content-type: image/png"); //告诉浏览器，下面的数据是图片，而不要按文字显示
Imagepng($this->img_cache); //生成png格式。。。嘿嘿效果蛮像回事的嘛。。。
ImageDestroy($this->img_cache);
}
else echo($this->img_cache);
}

//'----文件输出
function outputFile($filename=null)
{
if(!$filename)$filename=time().'.png';

$fp = fopen($filename, 'w+');
fwrite($fp, $this->img_cache);
fclose($fp);
}

//'----得到验证码
function getCheckNumber()
{
//srand(microtime() * 100000);//PHP420后，srand不是必须的
for($Tmpa=0;$Tmpa<$this->lenght;$Tmpa++)
{
$this->check_number.= $this->is_gd ? dechex(rand(0,15)) : rand(0,3);
}
unset($Tmpa);
$this->session['check_number'] = strtoupper($this->check_number);
}

//'----用GD库生成
function getFromGD()
{
//$black = '';

$this->img_cache = imageCreate($this->img_width,$this->img_height); //生成图片
//图片底色，ImageColorAllocate第1次定义颜色PHP就认为是底色了
$black = ImageColorAllocate($this->img_cache, 255,255,255);

//下面该生成雪花背景了，其实就是在图片上生成一些符号
//先用100个做测试
/*
for ($i=1; $i<=15; $i++)
{
imageString($this->img_cache,1,mt_rand(1,$this->img_height-10),mt_rand(1,$this->img_width-10),".",
imageColorAllocate($this->img_cache,mt_rand(100,255),mt_rand(0,250),mt_rand(0,200)));
//哈，看到了吧，其实也不是雪花，就是生成＊号而已。为了使它们看起来"杂乱无章、5颜6色"，就得在1个1个生成它们的时候，让它们的位置、颜色，甚至大小都用随机数，rand()或mt_rand都可以完成。
}
*/
//上面生成了背景，现在就该把已经生成的随机数放上来了。道理和上面差不多，随机数1个1个地放，同时让他们的位置、大小、颜色都用成随机数~~
//为了区别于背景，这里的颜色不超过200，上面的不小于200
imagettftext($this->img_cache, 20, 0, 10, 20, $black, "./html/VINERITC.TTF", "AC67");

for ($i=0;$i<strlen($this->session['check_number']);$i++)
{
imagettftext($this->img_cache, 14, rand(0,30), $i*$this->img_width/4 + 3, 17, imageColorAllocate($this->img_cache,mt_rand(0,100),mt_rand(0,150),mt_rand(0,200)), "./html/VINERITC.TTF", $this->session['check_number'][$i]);
}

for($i=0;$i<100;$i++)//加入干扰象素
{
imagesetpixel($this->img_cache, rand()%70 , rand()%30 , imageColorAllocate($this->img_cache,mt_rand(100,255),mt_rand(0,250),mt_rand(0,200)));
}

$black = ImageColorAllocate($this->img_cache, 0,0,0); //定义需要的黑色
//先成一黑色的矩形把图片包围
ImageRectangle($this->img_cache,0,0, $this->img_width-1,$this->img_height-1, $black);
}
//End Function getGD

#-----------------------------------------------------------------------------------------------------------------------
function set_4pixel($r, $g, $b, $x, $y)
{
$ofs = 3 * ($this->img_width * $y + $x);
$this->pixels[$ofs] = chr($r);
$this->pixels[$ofs + 1] = chr($g);
$this->pixels[$ofs + 2] = chr($b);
$this->pixels[$ofs + 3] = chr($r);
$this->pixels[$ofs + 4] = chr($g);
$this->pixels[$ofs + 5] = chr($b);
$ofs += 3 * $this->img_width;
$this->pixels[$ofs] = chr($r);
$this->pixels[$ofs + 1] = chr($g);
$this->pixels[$ofs + 2] = chr($b);
$this->pixels[$ofs + 3] = chr($r);
$this->pixels[$ofs + 4] = chr($g);
$this->pixels[$ofs + 5] = chr($b);
}

//生成数字图象的函数
function draw2digits($x, $y, $number)
{
//$this->draw_digit($x, $y, intval($number / 10) );
$this->draw_digit($x + 11, $y, $number % 10);
}
function draw_digit($x, $y, $digit)
{
$digit = $this->digits[$digit];
$m = 8;
for($b = 1, $i = 0; $i < 7; $i++, $b *= 2)
{
if(($b & $digit) == $b)
{
$j = $i * 4;
$x0 = $this->lines[$j] * $m + $x;
$y0 = $this->lines[$j + 1] * $m + $y;
$x1 = $this->lines[$j + 2] * $m + $x;
$y1 = $this->lines[$j + 3] * $m + $y;
if($x0 == $x1)
{
$ofs = 3 * ($this->img_width * $y0 + $x0);
for($h = $y0; $h <= $y1; $h++, $ofs += 3 * $this->img_width)
{
$this->pixels[$ofs] = chr(0);
$this->pixels[$ofs + 1] = chr(0);
$this->pixels[$ofs + 2] = chr(0);
}
}
else
{
$ofs = 3 * ($this->img_width * $y0 + $x0);
for($w = $x0; $w <= $x1; $w++)
{
$this->pixels[$ofs++] = chr(0);
$this->pixels[$ofs++] = chr(0);
$this->pixels[$ofs++] = chr(0);
}
}
}//End if
}//End for
}

//将文字加入到图象中
function add_chunk($type)
{
// chunk :为层
// length: 4 字节: 用来计算 chunk
// chunk type: 4 字节
// chunk data: length bytes
// CRC: 4 字节: 循环冗余码校验

// copy data and create CRC checksum
$len = strlen($this->data);
$this->chunk = pack("c*", ($len >> 24) & 255,
($len >> 16) & 255,
($len >> 8) & 255,
$len & 255);
$this->chunk .= $type;
$this->chunk .= $this->data;

//calculate a CRC checksum with the bytes chunk[4..len-1]
$z = 16777215;
$z |= 255 << 24;
$c = $z;
for ($n = 4; $n < strlen($this->chunk); $n++) {
$c8 = ($c >> 8) & 0xffffff;
$c = $this->crc_table[($c ^ ord($this->chunk[$n])) & 0xff] ^ $c8;
}
$crc = $c ^ $z;

$this->chunk .= chr(($crc >> 24) & 255);
$this->chunk .= chr(($crc >> 16) & 255);
$this->chunk .= chr(($crc >> 8) & 255);
$this->chunk .= chr($crc & 255);

//将结果加到$img_cache中
$this->img_cache .= $this->chunk;
}

//主程序
function getFromCode()
{
//填充
for($h = 0; $h < $this->img_height; $h++)
{
for($w = 0; $w < $this->img_width; $w++)
{
$r = 100 / $this->img_width * $w + 155;
$g = 100 / $this->img_height * $h + 155;
$b = 255 - (100 / ($this->img_width + $this->img_height) * ($w + $h));
$this->pixels .= chr($r);
$this->pixels .= chr($g);
$this->pixels .= chr($b);
}
}

$this->digits = array(95, 5, 118, 117, 45, 121, 123, 69, 127, 125);
$this->lines = array(1, 1, 1, 2, 0, 1, 0, 2, 1, 0, 1, 1, 0, 0, 0, 1, 0, 2, 1, 2, 0, 1, 1, 1, 0, 0, 1, 0);

for($i=0; $i<$this->lenght; $i++)
{
$this->draw2digits($i*13, 2, $this->check_number[$i]);
}
//$this->set_4pixel(0, 0, 0, 26, 7);
//$this->set_4pixel(0, 0, 0, 26, 13);
//$this->set_4pixel(0, 0, 0, 52, 7);
//$this->set_4pixel(0, 0, 0, 52, 13);

//创建循环冗余码校验表
$z = -306674912;// = 0xedb88320
for ($n = 0; $n < 256; $n++)
{
$c = $n;
for ($k = 0; $k < 8; $k++)
{
$c2 = ($c >> 1) & 0x7fffffff;
if($c & 1) $c = $z ^ ($c2);
else $c = $c2;
}
$this->crc_table[$n] = $c;
}

// PNG file signature
$this->img_cache = pack("c*", 137,80,78,71,13,10,26,10);

// IHDR chunk data:
// width: 4 bytes
// height: 4 bytes
// bit depth: 1 byte (8 bits per RGB value)
// color type: 1 byte (2 = RGB)
// compression method: 1 byte (0 = deflate/inflate)
// filter method: 1 byte (0 = adaptive filtering)
// interlace method: 1 byte (0 = no interlace)
$this->data = pack("c*", ($this->img_width>>24) & 255,
($this->img_width >> 16) & 255,
($this->img_width >> 8) & 255,
$this->img_width & 255,
($this->img_height >> 24) & 255,
($this->img_height >> 16) & 255,
($this->img_height >> 8) & 255,
$this->img_height & 255, 8, 2, 0, 0, 0);
$this->add_chunk("IHDR");

//以下不敢乱翻译，请自行参考
// scanline:
// filter byte: 0 = none
// RGB bytes for the line
// the scanline is compressed with "zlib", method 8 (RFC-1950):
// compression method/flags code: 1 byte ($78 = method 8, 32k window)
// additional flags/check bits: 1 byte ($01: FCHECK = 1, FDICT = 0, FLEVEL = 0)
// compressed data blocks: n bytes
// one block (RFC-1951):
// bit 0: BFINAL: 1 for the last block
// bit 1 and 2: BTYPE: 0 for no compression
// next 2 bytes: LEN (LSB first)
// next 2 bytes: one's complement of LEN
// LEN bytes uncompressed data
// check value: 4 bytes (Adler-32 checksum of the uncompressed data)
$len = ($this->img_width * 3 + 1) * $this->img_height;
$this->data = pack("c*", 0x78, 0x01, 1, $len & 255, ($len>>8) & 255, 255 - ($len & 255), 255 - (($len >> 8) & 255) );
$start = strlen($this->data);
$i2 = 0;
for($h = 0; $h < $this->img_height; $h++)
{
$this->data .= chr(0);
for($w = 0; $w < $this->img_width * 3; $w++)
{
$this->data .= $this->pixels[$i2++];
}
}

//calculate a Adler32 checksum with the bytes data[start..len-1]
$s1 = 1;
$s2 = 0;
for ($n = $start; $n < strlen($this->data); $n++)
{
$s1 = ($s1 + ord($this->data[$n])) % 65521;
$s2 = ($s2 + $s1) % 65521;
}
$adler = ($s2 << 16) | $s1;

$this->data .= chr(($adler >> 24) & 255);
$this->data .= chr(($adler >> 16) & 255);
$this->data .= chr(($adler >> 8) & 255);
$this->data .= chr($adler & 255);
$this->add_chunk("IDAT");

//IEND: marks the end of the PNG-file
$this->data = "";
$this->add_chunk("IEND");

//列印图象
//echo($this->img_cache);
}

}//End Class
?>