<?php
//設置方法
$cookie = new Cookie([
  'name' => 'cookie_monster',
  'value' => 'Me want cookie!',
  'expire' => time() + 86400 * 365,
]);
\Yii::$app->getResponse()->getCookies()->add($cookie);
//讀取方法
$value = \Yii::$app->getRequest()->getCookies()->getValue('my_cookie');
//給cookie加域名
$cookie = new Cookie([
  'name' => 'cookie_monster',
  'value' => 'Me want cookie everywhere!',
  'expire' => time() + 86400 * 365,
  'domain' => '.example.com' // <<<=== HERE
]);
\Yii::$app->getResponse()->getCookies()->add($cookie);
//設置登錄cookie
$config = [
  // ...
  'components' => [
    // ...
    'user' => [
      'class' => 'yii\web\User',
      'identityClass' => 'app\models\User',
      'enableAutoLogin' => true,
      'loginUrl' => '/user/login',
      'identityCookie' => [ // <---- here!
        'name' => '_identity',
        'httpOnly' => true,
        'domain' => '.example.com',
      ],
    ],
    'request' => [
      'cookieValidationKey' => 'your_validation_key'
    ],
    'session' => [
      'cookieParams' => [
        'domain' => '.example.com',
        'httpOnly' => true,
      ],
    ],
  ],
];
//只給批定目錄配置cookie
$config = [
  // ...
  'components' => [
    // ...
    'session' => [
      'name' => 'admin_session',
      'cookieParams' => [
        'httpOnly' => true,
        'path' => '/admin',
      ],
    ],
  ],
];
?>