验证码就是不显示
<?php
require_once 'string.func.php';
//通过GD库做验证码
function verifyImage($type=1,$length=4,$pixel=0,$line=0,$sess_name="verify"){
session_start();
//创建画布
$width=80;
$height=28;
$image=imagecreatetruecolor($width,$height);
$white=imagecolorallocate($image,255,255,255);
$black=imagecolorallocate($image,0,0,0);
//填充矩形填充画布
imagefilledrectangle($image,1,1,$width-2,$height-2,$white);
$chars=buildRandomString($type,$length);
$_SESSION[$sess_name]=$chars;
$fontfiles=array('msyh.ttf');
for($i=0;$i<$length;$i++){
$size=mt_rand(14,18);
$angle=mt_rand(-15,15);
$x=5+$i*$size;
$y=mt_rand(20,26);
$fontfile="../fonts/".$fontfiles[mt_rand(0,count($fontfiles)-1)];
$color=imagecolorallocate($image,mt_rand(50,90),mt_rand(0,255),mt_rand(0,255));
$text=substr($chars,$i,1);
imagettftext($image,$size,$angle,$x,$y,$color,$fontfile,$text);
}
if($pixel){
for($i=0;$i<50;$i++){
imagesetpixel($image,mt_rand(0,$width-1),mt_rand(0,$height-1),$black);
}
}
if($line){
for($i=1;$i<$line;$i++){
$color=imagecolorallocate($image,mt_rand(50,90),mt_rand(0,255),mt_rand(0,255));
imageline($image,mt_rand(0,$width-1),mt_rand(0,$height-1),mt_rand(0,$width-1),mt_rand(0,$height-1),$color);
}
}
header("content-type:image/gif");
imagegif($image);
imagedestroy($image);
}<?php
function buildRandomString($type=1,$length=4){
if($type==1){
$chars=join('',range(0,9));
}elseif($type==2){
$chars=join("",array_merge(range("a","z"),range("A","Z")));
}elseif($type==3){
$chars=join('',array_merge(range("a","z"),range("A","Z"),range(0,9)));
}
if($length>strlen($chars)){
exit('字符串长度不够');
}
$chars=str_shuffle($chars);
return substr($chars,0,$length);
}
