<?php

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
*/
require_once 'string.func.php';
    //通过GD库做验证码
    //创建画布
    $width=80;
    $height=20;
    $image = imagecreatetruecolor($width, $height);
    $whith = imagecolorallocate($image, 255,255, 255);
    $black = imagecolorallocate($image,0,0,0);
    //用填充矩形举行填充画布
    imagefilledrectangle($image,1,1,$width-2,$height-2,$white);
   $type=1;
   $length=4;
    $chars=buildRandomString($type,$length);
    $sess_name="verify";
    $_SESSION[$sess_name]=$chars;
    $fontfiles=array("msyh.ttf","msyhbd.ttf");
    for($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(80, 200), mt_rand(90, 250));
        $text=substr($chars,$i,1);
        imagettftext($image, $size, $angle, $x, $y, $color, $fontfiles, $text);
    }
 
    header("content-type:image/gif");
    imagegif($image);
    imagedestroy($image);

?>

<?php

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
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);
    substr($chars,0,$length);
}