Trying to Learn IoC and dependency injection

Inheritance IoC

<?

class mysqliWrapper extends mysqli
{
	function __construct()
	{
		/*
		This won't work since the parent constructor is generic, 
		and I want it constructed with the specific parameters defined by the IoC
		*/
		parent::__construct();

		/*
		This won't work you're prohibited from setting the $this variable, 
		*/
		$this = IoC::resolve('mysqli');
	}

	function __construct($mysqli)
	{
		$this->dependency1 = $mysqli->dependency1;
		/*
		This requires me to know all the dependencies for my parent class
		*/
	}
}

IoC::register('mysqliWrapper', function(){
	/* 
	Doing it this way requires me to repeat code, and know all
	the dependencies of the parent class, which I'm trying to avoid.
	*/
	$mysqliWrapper = new mysqliWrapper();
	$mysqliWrapper->dependency = '...';


	$mysqli = IoC::resolve('mysqli');
});

Registering A Mysqli Object

<?
//registering mysqli with the credentials specific to this project in the IoC
IoC::register('mysqli', function(){
	$host = 'localhost';
	$username = 'ProjectName_User';
	$password = 'somePassword';
	$database = 'Project_Database';

	return new mysqli($host, $username, $password, $database);

});

The IoC Class

//The IoC Class, Copied From Here: http://net.tutsplus.com/tutorials/php/dependency-injection-huh/

class IoC {
	/**
	* @var PDO The connection to the database
	*/
	protected static $registry = array();
 
	/**
	* Add a new resolver to the registry array.
	* @param  string $name The id
	* @param  object $resolve Closure that creates instance
	* @return void
	*/
	public static function register($name, Closure $resolve)
	{
		static::$registry[$name] = $resolve;
	}

	/**
	* Create the instance
	* @param  string $name The id
	* @return mixed
	*/
	public static function resolve($name)
	{
		if ( static::registered($name) )
		{
			$name = static::$registry[$name];
			return $name();	
		}
		else
		{
			throw new Exception('Nothing registered with that name.');
		}
	}
 
	/**
	* Determine whether the id is registered
	* @param  string $name The id
	* @return bool Whether to id exists or not
	*/
	public static function registered($name)
	{
	  return array_key_exists($name, static::$registry);
	}
		
}