php 绘制验证码 示例

 1 <?php
 2 header("content-type:image/jpeg");
 3 
 4 session_start();//开启session
 5 
 6 //宽高 字体大小
 7 $width=120;
 8 $height=40;
 9 $fontsize=20;
10 
11 //给画布宽高
12 $img=imagecreatetruecolor($width,$height);
13 
14 //画布背景色
15 $bgcolor=imagecolorallocate($img,rand(200,255),rand(200,255),rand(200,255));
16 
17  //画布边框背景
18 $bordercolor=imagecolorallocate($img,rand(0,155),rand(0,155),rand(0,155));
19 
20 //内容字体颜色
21 $fontcolor=imagecolorallocate($img,rand(30,100),rand(30,100),rand(30,100));
22 
23 //填充背景色
24 imagefill($img,0,0,$bgcolor);
25 
26 //填充边框
27 imagerectangle($img,0,0,$width-1,$height-1,$bordercolor);
28 
29 //干扰点
30 for($a=0;$a<100;$a++){
31     imagesetpixel($img,rand(1,$width-2),rand(1,$height-2),$bordercolor);
32 }
33 
34 //创建数组
35 $shuzi=range(0,9);
36 
37 //随机数
38 $suiji=$shuzi[rand(0,count($shuzi)-1)].$shuzi[rand(0,count($shuzi)-1)]
39     .$shuzi[rand(0,count($shuzi)-1)].$shuzi[rand(0,count($shuzi)-1)];
40 
41 //输出内容
42 imagettftext($img,$fontsize,rand(-5,5),rand(15,25),rand(28,33),$fontcolor,'ziti.ttf',$suiji);$_SESSION['yzm_b']=$suiji;
43 
44 //获取‘验证码输入框的内容’
45 
46 
47 
48 //输出画布
49 imagejpeg($img);
50 ?>
原文地址:https://www.cnblogs.com/weihexinCode/p/12318226.html