PHP編程
$session = Yii::$app->session;
// 檢查session是否開啟 
if ($session->isActive) ...
// 開啟session
$session->open();
// 關閉session
$session->close();
// 銷毀session中所有已注冊的數據
$session->destroy();

PHP編程
$session = Yii::$app->session;
// 獲取session中的變量值,以下用法是相同的：
$language = $session->get('language');
$language = $session['language'];
$language = isset($_SESSION['language']) ? $_SESSION['language'] : null;
// 設置一個session變量,以下用法是相同的：
$session->set('language', 'en-US');
$session['language'] = 'en-US';
$_SESSION['language'] = 'en-US';
// 刪除一個session變量,以下用法是相同的：
$session->remove('language');
unset($session['language']);
unset($_SESSION['language']);
// 檢查session變量是否已存在,以下用法是相同的：
if ($session->has('language')) ...
if (isset($session['language'])) ...
if (isset($_SESSION['language'])) ...
// 遍歷所有session變量,以下用法是相同的：
foreach ($session as $name => $value) ...
foreach ($_SESSION as $name => $value) ...

PHP編程
$session = Yii::$app->session;
// 如下代碼不會生效
$session['captcha']['number'] = 5;
$session['captcha']['lifetime'] = 3600;
// 如下代碼會生效：
$session['captcha'] = [
  'number' => 5,
  'lifetime' => 3600,
];
// 如下代碼也會生效：
echo $session['captcha']['lifetime'];

PHP編程
$session = Yii::$app->session;
// 直接使用$_SESSION (確保Yii::$app->session->open() 已經調用)
$_SESSION['captcha']['number'] = 5;
$_SESSION['captcha']['lifetime'] = 3600;
// 先獲取session數據到一個數組,修改數組的值,然后保存數組到session中
$captcha = $session['captcha'];
$captcha['number'] = 5;
$captcha['lifetime'] = 3600;
$session['captcha'] = $captcha;
// 使用ArrayObject 數組對象代替數組
$session['captcha'] = new \ArrayObject;
...
$session['captcha']['number'] = 5;
$session['captcha']['lifetime'] = 3600;
// 使用帶通用前綴的鍵來存儲數組
$session['captcha.number'] = 5;
$session['captcha.lifetime'] = 3600;

PHP編程
return [
  'components' => [
    'session' => [
      'class' => 'yii\web\DbSession',
      // 'db' => 'mydb', // 數據庫連接的應用組件ID,默認為'db'.
      // 'sessionTable' => 'my_session', // session 數據表名,默認為'session'.
    ],
  ],
];

PHP編程
CREATE TABLE session
(
  id CHAR(40) NOT NULL PRIMARY KEY,
  expire INTEGER,
  data BLOB
)

PHP編程
$session = Yii::$app->session;
// 哀求 #1
// 設置一個名為"postDeleted" flash 信息
$session->setFlash('postDeleted', 'You have successfully deleted your post.');
// 哀求 #2
// 顯示名為"postDeleted" flash 信息
echo $session->getFlash('postDeleted');
// 哀求 #3
// $result 為 false,因為flash信息已被自動刪除
$result = $session->hasFlash('postDeleted');

PHP編程
$session = Yii::$app->session;
// 哀求 #1
// 在名稱為"alerts"的flash信息增加數據
$session->addFlash('alerts', 'You have successfully deleted your post.');
$session->addFlash('alerts', 'You have successfully added a new friend.');
$session->addFlash('alerts', 'You are promoted.');
// 哀求 #2
// $alerts 為名為'alerts'的flash信息,為數組格式
$alerts = $session->getFlash('alerts');

PHP編程
// 從 "request"組件中獲取cookie集合(yii\web\CookieCollection)
$cookies = Yii::$app->request->cookies;
// 獲取名為 "language" cookie 的值,如果不存在,返回默認值"en"
$language = $cookies->getValue('language', 'en');
// 另一種方式獲取名為 "language" cookie 的值
if (($cookie = $cookies->get('language')) !== null) {
  $language = $cookie->value;
}
// 可將 $cookies當作數組使用
if (isset($cookies['language'])) {
  $language = $cookies['language']->value;
}
// 判斷是否存在名為"language" 的 cookie
if ($cookies->has('language')) ...
if (isset($cookies['language'])) ...

PHP編程
// 從"response"組件中獲取cookie 集合(yii\web\CookieCollection)
$cookies = Yii::$app->response->cookies;
// 在要發送的響應中添加一個新的cookie
$cookies->add(new \yii\web\Cookie([
  'name' => 'language',
  'value' => 'zh-CN',
]));
// 刪除一個cookie
$cookies->remove('language');
// 等同于以下刪除代碼
unset($cookies['language']);

PHP編程
return [
  'components' => [
    'request' => [
      'cookieValidationKey' => 'fill in a secret key here',
    ],
  ],
];