$(‘#id').on("click",function() {});

 public function onBeginRequest($event){
 $this->raiseEvent('onBeginRequest',$event);
}

/** * Raises an event. 
  * This method represents the happening of an event. It invokes 
  * all attached handlers for the event. 
  * @param string $name the event name 
  * @param CEvent $event the event parameter 
  * @throws CException if the event is undefined or an event handler is invalid. 
*/

  public function raiseEvent($name,$event){  
       $name=strtolower($name);  
       //_e这个数组用来存所有事件信息
       if(isset($this->_e[$name]))  {   
          foreach($this->_e[$name] as $handler) {     
            if(is_string($handler)) 
              call_user_func($handler,$event);       
            elseif(is_callable($handler,true)){ 
                 if(is_array($handler)){        
                   // an array: 0 - object, 1 - method name  
                   list($object,$method)=$handler;   
                   if(is_string($object)) // static method call 
                    call_user_func($handler,$event); 
                   elseif(method_exists($object,$method))     
                     $object->$method($event);        
                   else         
                     throw new CException(Yii::t('yii','Event "{class}.{event}" is attached with an invalid handler "{handler}".',  array('{class}'=>get_class($this), '{event}'=>$name, '{handler}'=>$handler[1])));      
                  }      
                  else // PHP 5.3: anonymous function 
                     call_user_func($handler,$event);     
            }     
            else      
              throw new CException(Yii::t('yii','Event "{class}.{event}" is attached with an invalid handler "{handler}".', array('{class}'=>get_class($this), '{event}'=>$name, '{handler}'=>gettype($handler))));     
           // stop further handling if param.handled is set true 
            if(($event instanceof CEvent) && $event->handled) 
              return;   
          } 
        }  elseif(YII_DEBUG && !$this->hasEvent($name))   
          throw new CException(Yii::t('yii','Event "{class}.{event}" is not defined.',     array('{class}'=>get_class($this), '{event}'=>$name)));
 }

function ($event) {
  // $event 是 yii\base\Event 或其子类的对象
}

$foo = new Foo;

// 处理器是全局函数
$foo->on(Foo::EVENT_HELLO, 'function_name');

// 处理器是对象方法
$foo->on(Foo::EVENT_HELLO, [$object, 'methodName']);

// 处理器是静态类方法
$foo->on(Foo::EVENT_HELLO, ['app\components\Bar', 'methodName']);

// 处理器是匿名函数
$foo->on(Foo::EVENT_HELLO, function ($event) {
  //事件处理逻辑
});
附加事件处理器时可以提供额外数据作为 yii\base\Component::on() 方法的第三个参数。数据在事件被触发和处理器被调用时能被处理器使用。如：

// 当事件被触发时以下代码显示 "abc"
// 因为 $event->data 包括被传递到 "on" 方法的数据
$foo->on(Foo::EVENT_HELLO, function ($event) {
  echo $event->data;
}, 'abc');

$foo->on(Foo::EVENT_HELLO, function ($event) {
  $event->handled = true;
});

$foo->on(Foo::EVENT_HELLO, function ($event) {
  // 这个处理器将被插入到处理器队列的第一位...
}, $data, false);

namespace app\components;

use yii\base\Component;
use yii\base\Event;

class Foo extends Component
{
  const EVENT_HELLO = 'hello';

  public function bar()
  {
    $this->trigger(self::EVENT_HELLO);
  }
}

namespace app\components;

use yii\base\Component;
use yii\base\Event;

class MessageEvent extends Event
{
  public $message;
}

class Mailer extends Component
{
  const EVENT_MESSAGE_SENT = 'messageSent';

  public function send($message)
  {
    // ...发送 $message 的逻辑...

    $event = new MessageEvent;
    $event->message = $message;
    $this->trigger(self::EVENT_MESSAGE_SENT, $event);
  }
}

// 处理器是全局函数
$foo->off(Foo::EVENT_HELLO, 'function_name');

// 处理器是对象方法
$foo->off(Foo::EVENT_HELLO, [$object, 'methodName']);

// 处理器是静态类方法
$foo->off(Foo::EVENT_HELLO, ['app\components\Bar', 'methodName']);

// 处理器是匿名函数
$foo->off(Foo::EVENT_HELLO, $anonymousFunction);

$foo->off(Foo::EVENT_HELLO);

use Yii;
use yii\base\Event;
use yii\db\ActiveRecord;

Event::on(ActiveRecord::className(), ActiveRecord::EVENT_AFTER_INSERT, function ($event) {
  Yii::trace(get_class($event->sender) . ' is inserted');
});

use yii\base\Event;

Event::on(Foo::className(), Foo::EVENT_HELLO, function ($event) {
  echo $event->sender; // 显示 "app\models\Foo"
});

Event::trigger(Foo::className(), Foo::EVENT_HELLO);

// 移除 $handler
Event::off(Foo::className(), Foo::EVENT_HELLO, $handler);

// 移除 Foo::EVENT_HELLO 事件的全部处理器
Event::off(Foo::className(), Foo::EVENT_HELLO);

use Yii;
use yii\base\Event;
use app\components\Foo;

Yii::$app->on('bar', function ($event) {
  echo get_class($event->sender); // 显示 "app\components\Foo"
});

Yii::$app->trigger('bar', new Event(['sender' => new Foo]));

$component->attachEventHandler($name, $handler);
$component->onBeginRequest = $handler ;

Yii::app()->attachEventHandler('onEndRequest',array($this,'processLogs'));

if($this->hasEventHandler('onBeginRequest'))
  $this->onBeginRequest(new CEvent($this));

call_user_func(‘print', $str);

call_user_func(array(‘className', ‘print'), $str );

$obj = new className();
call_user_func(array($obj, ‘print'), $str );

call_user_func(function($i){echo $i++;},4);

$s = function($i) {
  echo $i++;
};
call_user_func($s,4);