ck.func.php

PHP+IIS+MySQL开发物流管理系统

<?php
#[验证码]
function SetCheckCodes()
{
	$x_size=90;
	$y_size=30;
	if(function_exists("imagecreate"))
	{
		$aimg = imagecreate($x_size,$y_size);
		$back = imagecolorallocate($aimg, 255, 255, 255);
		$border = imagecolorallocate($aimg, 0, 0, 0);
		imagefilledrectangle($aimg, 0, 0, $x_size - 1, $y_size - 1, $back);	
		$font = 'tahoma.ttf';
		$txt="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
		$txtlen=strlen($txt);
		
		$thetxt="";	
		for($i=0;$i<4;$i++)
		{
			$randnum=mt_rand(0,$txtlen-1);
			$randang=mt_rand(-20,20);	//文字旋转角度
			$rndtxt=substr($txt,$randnum,1);
			$thetxt.=$rndtxt;
			$rndx=mt_rand(2,7);
			$rndy=mt_rand(0,9);	
			$colornum1=($rndx*$rndx*$randnum)%255;
			$colornum2=($rndy*$rndy*$randnum)%255;
			$colornum3=($rndx*$rndy*$randnum)%255;		
			$newcolor=imagecolorallocate($aimg, $colornum1, $colornum2, $colornum3);
			if(function_exists("imagettftext"))
			{
				imagettftext($aimg, 14, $randang, $rndx+$i*21, 16+$rndy, $border, $font, $rndtxt);	
				imagettftext($aimg, 14, $randang, $rndx+$i*21+1, 16+$rndy+1, $newcolor, $font, $rndtxt);
			}
			else
			{
				imageString($aimg,5,$rndx+$i*21,5+$rndy,$rndtxt,$newcolor);
			}

		}
		unset($txt);
		$thetxt = strtolower($thetxt);
		setcookie("qgLoginChk",md5($thetxt),time()+1800,"/");
		imagerectangle($aimg, 0, 0, $x_size - 1, $y_size - 1, $border);

		$newcolor="";
		$newx="";
		$newy="";
		$pxsum=150;	//干扰像素个数
		for($i=0;$i<$pxsum;$i++)
		{
			$newcolor=imagecolorallocate($aimg, mt_rand(0,254), mt_rand(0,254), mt_rand(0,254));
			imagesetpixel($aimg,mt_rand(0,$x_size-1),mt_rand(0,$y_size-1),$newcolor);
		}
		header("Pragma:no-cache");
		header("Cache-control:no-cache");
		header("Content-type: image/png");
		imagepng($aimg);
		imagedestroy($aimg);
		exit;
	}
}

SetCheckCodes();
?>