圖形數(shù)字驗(yàn)證代碼 Code:   <?

/*

* Filename: authpage.php

*/



srand((double)microtime()*1000000);



//驗(yàn)證用戶輸入是否和驗(yàn)證碼一致

if(isset($_POST['authinput']))

{


if(strcmp($_POST['authnum'],$_POST['authinput'])==0)

echo "驗(yàn)證成功！";

else

echo "驗(yàn)證失??！";

}



//生成新的四位整數(shù)驗(yàn)證碼

while(($authnum=rand()%10000)<1000);

?>

<form action=authpage.php method=post>

<table>

請輸入驗(yàn)證碼：<input type=text name=authinput style="width: 80px"><br>

<input type=submit name="驗(yàn)證" value="提交驗(yàn)證碼">

<input type=hidden name=authnum value=<? echo $authnum; ?>>

<img src=authimg.php?authnum=<? echo $authnum; ?>>

</table>

</form>

-------------------------------------------------------------------------------------------------------------

<?
/*

* Filename: authimg.php

*/
//生成驗(yàn)證碼圖片
Header("Content-type: image/PNG");

srand((double)microtime()*1000000);

$im = imagecreate(58,28);

$black = ImageColorAllocate($im, 0,0,0);

$white = ImageColorAllocate($im, 255,255,255);

$gray = ImageColorAllocate($im, 200,200,200);

imagefill($im,68,30,$gray);



//將四位整數(shù)驗(yàn)證碼繪入圖片

imagestring($im, 5, 10, 8, $HTTP_GET_VARS['authnum'], $white);



for($i=0;$i<50;$i++) //加入干擾象素

{

imagesetpixel($im, rand()%70 , rand()%30 , $gray);

}



ImagePNG($im);

ImageDestroy($im);

?>