composer require gregwar/captcha

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use Gregwar\Captcha\CaptchaBuilder;

use Gregwar\Captcha\PhraseBuilder;

class IndexController extends Controller

{

    public function index()

    {

        return view('index');

    }

    /**

    * 设置并输出图片

    */

    public function getCaptcha()

    {

        $phrase = new PhraseBuilder;

        // 设置验证码位数

        $code = $phrase->build(5);

        // 生成验证码图片的Builder对象,配置相应属性

        $builder = new CaptchaBuilder($code, $phrase);

        // 设置背景颜色25,25,112

        $builder->setBackgroundColor(25, 25, 112);

        // 设置倾斜角度

        $builder->setMaxAngle(25);

        // 设置验证码后面最大行数

        $builder->setMaxBehindLines(10);

        // 设置验证码前面最大行数

        $builder->setMaxFrontLines(10);

        // 设置验证码颜色

        $builder->setTextColor(255, 255, 0);

        // 可以设置图片宽高及字体

        $builder->build($width = 150, $height = 40, $font = null);

        // 获取验证码的内容

        $phrase = $builder->getPhrase();

        // 把内容存入session

        session()->put('CAPTCHA_IMG', $phrase);

        // 生成图片

        header('Cache-Control: no-cache, must-revalidate');

        header('Content-Type:image/jpeg');

        $builder->output();

    }

}