掌握Laravel框架中容器的管理依赖实现松耦合

public function __construct(Application $app)
    {
        $this->app = $app;
    }

public function handle($request, Closure $next, ...$guards)
    {
        $this->authenticate($request, $guards);
        return $next($request);
    }

use?App\Repositories\UserRepository;
use?App\Services\UserService;
use?Illuminate\Contracts\Container\Container;
class?UserController?extends?Controller
{
????protected?$container;
????public?function?__construct(Container?$container)
????{
????????$this->container?=?$container;
????}
????public?function?getUser($id)
????{
????????$userService?=?$this->container->make(UserService::class,?[
????????????'userRepository'?=>?$this->container->make(UserRepository::class),
????????]);
????????$user?=?$userService->getUser($id);
????????return?view('user',?compact('user'));
????}
}

class A
{
    protected $b;
    public function __construct(B $b) {
        $this->b = $b;
    }
    public function getB(){
        return $this->b->bMethod();
    }
}
class B 
{
    public function __construct() {}
    public function bMethod(){
        return "Hello World!";
    }
}
// IOC容器类
class Ioc
{
    protected $instances = [];
    public function __construct() {
        $this->instances['B'] = new B();
        $this->instances['C'] = new C();
        $this->instances['D'] = new D();
    }
    public function make($abstract){
        return $this->instances[$abstract];
    }
}
// 控制反转：类与类的依赖关系不再在类A中创建，
// 而是通过IOC容器生成类B后通过参数的形式传入类A中；
$ioc = new Ioc();
$b   = $ioc->make('B');
$a   = new A($b);
$a->getB();

ReflectionClass 报告了一个类的有关信息
ReflectionClass::getConstructor — 获取类的构造函数
ReflectionClass::getConstructor::getParameters — 获取到Constructor的属性值
ReflectionClass::newInstanceArgs — 从给出的参数创建一个新的类实例。
ReflectionParameter::getClass — 获得类型提示类。
ReflectionParameter::isDefaultValueAvailable — 检查是否有默认值。
ReflectionParameter::getDefaultValue — 获取到默认的属性值

//获取类的反射信息,也就是类的所有信息
$reflector = new ReflectionClass(类名);
 echo $reflector->getDocComment();  获取类的注释信息
//获取反射类的构造函数信息
$constructor = $reflector->getConstructor();
//获取反射类的构造函数的参数
$dependencies = $constructor->getParameters();