PHP教程
<?php 
namespace App\Http\Controllers;
use App\Http\Requests;
use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
//引用對應的命名空間
use Gregwar\Captcha\CaptchaBuilder;
use Session;
class CodeController extends Controller{
 public function captcha($temp)
 {
  $builder = new CaptchaBuilder();
  $builder->build(150,32);
  $phrase = $builder->getPhrase();
  //把內容存入session
  Session::flash('milkcaptcha', $phrase); //存儲驗證碼
  ob_clean();
  return response($builder->output())->header('Content-type','image/jpeg');
 }
}

PHP教程
public function code($tmp)
{
//生成驗證碼圖片的Builder對象,配置相應屬性
$builder = new CaptchaBuilder;
//可以設置圖片寬高及字體
$builder->build($width = 100, $height = 40, $font = null);
//獲取驗證碼的內容
$phrase = $builder->getPhrase();
//把內容存入session
Session::flash('milkcaptcha', $phrase);
//生成圖片
header("Cache-Control: no-cache, must-revalidate");
header('Content-Type: image/jpeg');
$builder->output();
}

PHP教程
public function captcha($temp)
 {
  $builder = new CaptchaBuilder();
  $builder->build(150,32);
  $phrase = $builder->getPhrase();
  //把內容存入session
  Session::flash('milkcaptcha', $phrase); //存儲驗證碼
  ob_clean();
  return response($builder->output())->header('Content-type','image/jpeg');
 }