本文實例講述了PHP實現事件機制的方法。分享給大家供大家參考。具體如下：

<?php

/**

* 事件

*/

class Event {

private $callbacks = array();

private $holder;

function __construct() {

$bt = debug_backtrace();

if (count($bt) < 2) {

$this->holder = null;

return;

}

$this->holder = &$bt[1]['object'];

}

function attach() {

$args = func_get_args();

switch (count($args)) {

case 1:

if (is_callable($args[0])) {

$this->callbacks[]= $args[0];

return;

}

break;

case 2:

if (is_object($args[0]) && is_string($args[1])) {

$this->callbacks[]= array(&$args[0], $args[1]);

}

return;

default:

return;

}

}

function notify() {

$bt = debug_backtrace();

if ($this->holder &&

((count($bt) >= 2 && $bt[count($bt) - 1]['object'] !== $this->holder)

|| (count($bt) < 2))) {

throw(new Exception('Notify can only be called in holder'));

}

foreach ($this->callbacks as $callback) {

$args = func_get_args();

call_user_func_array($callback, $args);

}

}

}

希望本文所述對大家的php程序設計有所幫助。