<?php
//设置方法
$cookie = new Cookie([
    'name' => 'cookie_monster',
    'value' => 'Me want cookie!',
    'expire' => time() + 86400 * 365,
]);
\Yii::$app->getResponse()->getCookies()->add($cookie);
//读取方法
$value = \Yii::$app->getRequest()->getCookies()->getValue('my_cookie');
//给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);
//设置登录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,
            ],
        ],

    ],
];
//只给批定目录配置cookie
$config = [
    // ...
    'components' => [
        // ...
        'session' => [
            'name' => 'admin_session',
            'cookieParams' => [
                'httpOnly' => true,
                'path' => '/admin',
            ],
        ],
    ],
];
?>