使用依赖注入框架，开发人员不需要手动准备和设置类实例的依赖项，这一切都是事先准备好的。

对于工厂，开发人员必须手工完成，并使用这些依赖对象创建类实例。

区别主要在于这一行中调用工厂并获取构造的对象，以及编写工厂方法来创建和设置所有内容(尽管可以认为，在依赖注入框架中，通过连接和配置对象关系，这也必须在一定程度上完成)。

如果是工厂，你就得打电话给任何需要这种东西的工厂。 使用依赖注入框架，你可以在类实例创建时依赖对象的存在。

我的观点是，工厂方法更静态，因为它的实现相当固定，而依赖注入框架更动态，因为类实例的实际组合更容易改变(例如。为了测试目的)在运行时。

如果传递的参数可以在工厂中分组，那么它也是构造函数过度注入的一个很好的解决方案，看看下面的代码*):

public AddressModelFactory(IAddressAttributeService addressAttributeService,
        IAddressAttributeParser addressAttributeParser,
        ILocalizationService localizationService,
        IStateProvinceService stateProvinceService,
        IAddressAttributeFormatter addressAttributeFormatter)
    {
        this._addressAttributeService = addressAttributeService;
        this._addressAttributeParser = addressAttributeParser;
        this._localizationService = localizationService;
        this._stateProvinceService = stateProvinceService;
        this._addressAttributeFormatter = addressAttributeFormatter;
    }

看看构造函数，你只需要在那里传递IAddressModelFactory，所以参数更少*):

 public CustomerController(IAddressModelFactory addressModelFactory,
        ICustomerModelFactory customerModelFactory,
        IAuthenticationService authenticationService,
        DateTimeSettings dateTimeSettings,
        TaxSettings taxSettings,
        ILocalizationService localizationService,
        IWorkContext workContext,
        IStoreContext storeContext,
        ICustomerService customerService,
        ICustomerAttributeParser customerAttributeParser,
        ICustomerAttributeService customerAttributeService,
        IGenericAttributeService genericAttributeService,
        ICustomerRegistrationService customerRegistrationService,
        ITaxService taxService,
        CustomerSettings customerSettings,
        AddressSettings addressSettings,...

你可以看到在CustomerController中传递了很多参数，是的，你可以看到这是构造函数的过度注入，但这就是DI的工作方式。CustomerController没有任何问题。

*)代码来自nopCommerce。

当我读到关于DI的文章时，我也有同样的问题。 最后，这就是我所理解的，但如果我错了，请纠正我。

“很久以前，有一些小国，它们有自己的管理机构，根据自己的成文规则进行控制和决策。后来形成了一个大政府，消除了所有这些小的管理机构，这些机构只有一套规则(宪法)，并通过法院执行。”

小王国的管理机构是“工厂”

大政府是“依赖注入器”。

Life cycle management is one of the responsibilities dependency containers assume in addition to instantiation and injection. The fact that the container sometimes keep a reference to the components after instantiation is the reason it is called a "container", and not a factory. Dependency injection containers usually only keep a reference to objects it needs to manage life cycles for, or that are reused for future injections, like singletons or flyweights. When configured to create new instances of some components for each call to the container, the container usually just forgets about the created object.

来自:http://tutorials.jenkov.com/dependency-injection/dependency-injection-containers.html

IOC is a concept which is implemented by two ways. Dependency creation and dependency injection, Factory/Abstract factory are the example of dependency creation. Dependency injection is constructor, setter and interface. The core of IOC is to not depend upon the concrete classes, but define the abstract of methods(say an Interface/abstract class) and use that abstract to call method of concrete class. Like Factory pattern return the base class or interface. Similariliy dependency injection use base class/interface to set value for objects.

依赖注入的一个缺点是它不能用逻辑初始化对象。例如，当我需要创建一个随机名称和年龄的字符时，DI不是工厂模式的选择。使用工厂，我们可以很容易地从对象创建中封装随机算法，它支持一种称为“封装变化”的设计模式。