<?php
/**
* 驗證碼測試
* @author zcs
*/
session_start();
$_SESSION['valid']= randstr();
echo $_SESSION['valid']; //隨機產生字串 function randstr($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” />
產生gif動態驗證碼
PHP產生GIF動畫來實現動態圖片驗證碼，以下是實現過程。 ImageCode函數通過GIFEncoder類實現的GIF動畫
/**
* ImageCode 產生GIF圖片驗證
* @param $string 字串
* @param $width 寬度
* @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 = $height;
// 產生一個32幀的GIF動畫
for($i = 0; $i < 32; $i++)
{
ob_start();
$image = imagecreate($board_width, $board_height);
imagecolorallocate($image, 0,0,0);
// 設定文字顏色數組
$colorList[] = ImageColorAllocate($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);
$space = 15; // 字元間距
if($i > 0) // 屏蔽第一幀
{
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]);
}
// 添加幹擾線
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 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=utf-8" />
<title>無標題文檔</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">驗證碼：</label>
<input type="text" name="code" id="textfield" />
<img id="imgcode" src="VerifyCode.php" alt="驗證碼" />
<a href="javascript:refresh_code()">看不清？換一個</a>
<input type="submit" name="button" id="button" value="提交" />
</form>
</body>
</html> |
