Class yii\web\Session

Adds a flash message.

If there are existing flash messages with the same key, the new one will be appended to the existing message array.

参见：

• getFlash()
• setFlash()
• removeFlash()

Ends the current session and store session data.

Session close handler.

This method should be overridden if $useCustomStorage returns true.

Returns the number of items in the session.

This method is required by Countable interface.

Frees all session variables and destroys all data registered to a session.

This method has no effect when session is not active. Make sure to call open() before calling it.

参见：

• open()
• $isActive

Session destroy handler.

This method should be overridden if $useCustomStorage returns true.

If session is started it's not possible to edit session ini settings. In PHP7.2+ it throws exception.

This function saves session data to temporary variable and stop session.

Session GC (garbage collection) handler.

This method should be overridden if $useCustomStorage returns true.

Returns the session variable value with the session variable name.

If the session variable does not exist, the $defaultValue will be returned.

Returns all flash messages.

You may use this method to display all the flash messages in a view file:

<?php
foreach (Yii::$app->session->getAllFlashes() as $key => $message) {
    echo '<div class="alert alert-' . $key . '">' . $message . '</div>';
} ?>

With the above code you can use the bootstrap alert classes such as success, info, danger as the flash message key to influence the color of the div.

Note that if you use addFlash(), $message will be an array, and you will have to adjust the above code.

参见：

• setFlash()
• addFlash()
• getFlash()
• hasFlash()
• removeFlash()

Returns current cache limiter

参见 http://php.net/manual/en/function.session-get-cookie-params.php.

Returns the number of items in the session.

Returns a flash message.

参见：

• setFlash()
• addFlash()
• hasFlash()
• getAllFlashes()
• removeFlash()

Returns a value indicating whether the current request has sent the session ID.

The default implementation will check cookie and $_GET using the session name. If you send session ID via other ways, you may need to override this method or call setHasSessionId() to explicitly set whether the session ID is sent.

Gets the session ID.

This is a wrapper for PHP session_id().

Returns an iterator for traversing the session variables.

This method is required by the interface IteratorAggregate.

Gets the name of the current session.

This is a wrapper for PHP session_name().

Gets the current session save path.

This is a wrapper for PHP session_save_path().

Returns the value indicating whether cookies should be used to store session IDs.

参见 setUseCookies().

Returns a value indicating whether to use custom session storage.

This method should be overridden to return true by child classes that implement custom session storage. To implement custom session storage, override these methods: openSession(), closeSession(), readSession(), writeSession(), destroySession() and gcSession().

Returns a value indicating whether there are flash messages associated with the specified key.

Initializes the application component.

This method is required by IApplicationComponent and is invoked by application.

This method is required by the interface ArrayAccess.

This method is required by the interface ArrayAccess.

This method is required by the interface ArrayAccess.

This method is required by the interface ArrayAccess.

Starts the session.

Session open handler.

This method should be overridden if $useCustomStorage returns true.

Session read handler.

This method should be overridden if $useCustomStorage returns true.

Updates the current session ID with a newly generated one.

Please refer to http://php.net/session_regenerate_id for more details.

This method has no effect when session is not active. Make sure to call open() before calling it.

参见：

• open()
• $isActive

Registers session handler.

Removes a session variable.

Removes all session variables.

Removes all flash messages.

Note that flash messages and normal session variables share the same name space. If you have a normal session variable using the same name, it will be removed by this method.

参见：

• getFlash()
• setFlash()
• addFlash()
• removeFlash()

Removes a flash message.

参见：

• getFlash()
• setFlash()
• addFlash()
• removeAllFlashes()

Adds a session variable.

If the specified name already exists, the old value will be overwritten.

Set cache limiter

Sets the session cookie parameters.

The cookie parameters passed to this method will be merged with the result of session_get_cookie_params().

参见 http://us2.php.net/manual/en/function.session-set-cookie-params.php.

Sets a flash message.

A flash message will be automatically deleted after it is accessed in a request and the deletion will happen in the next request. If there is already an existing flash message with the same key, it will be overwritten by the new one.

参见：

• getFlash()
• addFlash()
• removeFlash()

Sets the value indicating whether the current request has sent the session ID.

This method is provided so that you can override the default way of determining whether the session ID is sent.

Sets the session ID.

This is a wrapper for PHP session_id().

Sets the name for the current session.

This is a wrapper for PHP session_name().

Sets the current session save path.

This is a wrapper for PHP session_save_path().

Sets the value indicating whether cookies should be used to store session IDs.

Three states are possible:

• true: cookies and only cookies will be used to store session IDs.
• false: cookies will not be used to store session IDs.
• null: if possible, cookies will be used to store session IDs; if not, other mechanisms will be used (e.g. GET parameter)

Starts session and restores data from temporary variable

Updates the counters for flash messages and removes outdated flash messages.

This method should only be called once in init().

Session write handler.

This method should be overridden if $useCustomStorage returns true.