<?php
class Di implements \ArrayAccess{private $_bindings = array();//服务列表private $_instances = array();//已经实例化的服务//获取服务public function get($name,$params=array()){//先从已经实例化的列表中查找if(isset($this->_instances[$name])){return $this->_instances[$name];}//检测有没有注册该服务if(!isset($this->_bindings[$name])){return null;}$concrete = $this->_bindings[$name]['class'];//对象具体注册内容$obj = null;//匿名函数方式if($concrete instanceof \Closure){$obj = call_user_func_array($concrete,$params);}//字符串方式elseif(is_string($concrete)){if(empty($params)){$obj = new $concrete;}else{//带参数的类实例化，使用反射$class = new \ReflectionClass($concrete);$obj = $class->newInstanceArgs($params);}}//如果是共享服务，则写入_instances列表，下次直接取回if($this->_bindings[$name]['shared'] == true && $obj){$this->_instances[$name] = $obj;}return $obj;}//检测是否已经绑定public function has($name){return isset($this->_bindings[$name]) or isset($this->_instances[$name]);}//卸载服务public function remove($name){unset($this->_bindings[$name],$this->_instances[$name]);}//设置服务public function set($name,$class){$this->_registerService($name, $class);}//设置共享服务public function setShared($name,$class){$this->_registerService($name, $class, true);}//注册服务private function _registerService($name,$class,$shared=false){$this->remove($name);if(!($class instanceof \Closure) && is_object($class)){$this->_instances[$name] = $class;}else{$this->_bindings[$name] = array("class"=>$class,"shared"=>$shared);}}//ArrayAccess接口,检测服务是否存在public function offsetExists($offset) {return $this->has($offset);}//ArrayAccess接口,以$di[$name]方式获取服务public function offsetGet($offset) {return $this->get($offset);}//ArrayAccess接口,以$di[$name]=$value方式注册服务，非共享public function offsetSet($offset, $value) {return $this->set($offset,$value);}//ArrayAccess接口,以unset($di[$name])方式卸载服务public function offsetUnset($offset) {return $this->remove($offset);}
}

<?php
header("Content-Type:text/html;charset=utf8");
class A{public $name;public $age;public function __construct($name=""){$this->name = $name;}
}include "Di.class.php";
$di = new Di();
//匿名函数方式注册一个名为a1的服务
$di->setShared('a1',function($name=""){return new A($name);
});
//直接以类名方式注册
$di->set('a2','A');
//直接传入实例化的对象
$di->set('a3',new A("小唐"));$a1 = $di->get('a1',array("小李"));
echo $a1->name."<br/>";//小李
$a1_1 = $di->get('a1',array("小王"));
echo $a1->name."<br/>";//小李
echo $a1_1->name."<br/>";//小李$a2 = $di->get('a2',array("小张"));
echo $a2->name."<br/>";//小张
$a2_1 = $di->get('a2',array("小徐"));
echo $a2->name."<br/>";//小张
echo $a2_1->name."<br/>";//小徐$a3 = $di['a3'];//可以直接通过数组方式获取服务对象
echo $a3->name."<br/>";//小唐