lylme_spage/include/validatecode.php

<?php
/* 
 * @Description: 
 * @Author: LyLme admin@lylme.com
 * @Date: 2024-01-23 12:25:35
 * @LastEditors: LyLme admin@lylme.com
 * @LastEditTime: 2024-04-06 16:08:52
 * @FilePath: /lylme_spage/include/validatecode.php
 * @Copyright (c) 2024 by LyLme, All Rights Reserved. 
 */

session_start();

$image = imagecreatetruecolor(100, 38);    //1>设置验证码图片大小的函数
//5>设置验证码颜色 imagecolorallocate(int im, int red, int green, int blue);
$bgcolor = imagecolorallocate($image, 255, 255, 255); //#ffffff
//6>区域填充 int imagefill(int im, int x, int y, int col) (x,y) 所在的区域着色,col 表示欲涂上的颜色
imagefill($image, 0, 0, $bgcolor);
//10>设置变量

$captcha_code = "";
//9>增加干扰元素，设置横线
for ($i = 0; $i < 15; $i++) {
    //设置线的颜色
    $linecolor = imagecolorallocate($image, rand(70, 90),rand(70, 90), rand(70, 90));
    //设置线，两点一线
    imageline($image, rand(1, 38), rand(1, 99), rand(1, 99), rand(1, 38), $linecolor);

}
//7>生成随机数字
for ($i = 0; $i < 5; $i++) {
    //设置字体大小
    $fontsize = 8;
    //设置字体颜色，随机颜色
    $fontcolor = imagecolorallocate($image, rand(30, 80) ,rand(30, 80) ,rand(30, 80) );      
    //设置数字
    $fontcontent = rand(0, 9);
    //10>.=连续定义变量
    $captcha_code .= $fontcontent;
    //设置坐标
    $x = ($i * 100 / 5) + rand(5, 10);
    $y = rand(5, 20);

    imagestring($image, $fontsize, $x, $y, $fontcontent, $fontcolor);
}
//10>存到session
$_SESSION['authcode'] = $captcha_code;
//8>增加干扰元素，设置雪花点
for ($i = 0; $i < 30; $i++) {
    //设置点的颜色，50-200颜色比数字浅，不干扰阅读
    $pointcolor = imagecolorallocate($image, rand(80, 90) , rand(80, 90) , rand(80, 90) );
    //imagesetpixel — 画一个单一像素
    imagesetpixel($image, rand(1, 99), rand(1, 38), $pointcolor);
    imagesetpixel($image, rand(1, 99), rand(1, 38), $pointcolor);
    imagesetpixel($image, rand(1, 99), rand(1, 38), $pointcolor);
}


//2>设置头部，image/png
header('Content-Type: image/png');
//3>imagepng() 建立png图形函数
imagepng($image);
//4>imagedestroy() 结束图形函数 销毁$image
imagedestroy($image);