匕首2基类注射

本文介绍了匕首2基类注射的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

在匕首1我有一个基类的设置，这样它会处理创建范围的图形和依赖注入到当前对象。例如...

In Dagger 1 I had a base class setup such that it would handle creating a scoped graph and injecting dependencies into the current object. For example...

public abstract class MyBaseActivity extends Activity { private ObjectGraph graph; protected void onCreate(Bundle savedInstanceState) { graph = ((MyApp) getApplication()).plus(getModules()); graph.inject(this); } protected Object[] getModules(); } public class MyClass extends MyBaseActivity { @Inject SomeDep someDep; @Override protected Object[] getModules() { return new Object[/* Contains a module that provides SomeDep */]; } }

这允许每个子类，以补充其自己的一组模块中除了一个标准应用模块。

This allowed for each subclass to supplement their own set of modules in addition to a standard application module.

在用匕首2玩弄，它似乎并不能够处理类似的情景......

After playing around with Dagger 2, it doesn't seem possible to handle a similar scenario...

public abstract class MyBaseActivity extends Activity { private MyBaseActivityComponent component; protected void onCreate(Bundle savedInstanceState) { component = ((MyApp) getApplication())ponent().plus(/* Can not accept an array */); component.inject(this); } }

我的工作上面的周围通过修改MyBaseActivityComponent这样它会列出它所有可能​​用到的模块...

I worked around the above by modifying MyBaseActivityComponent such that it would list all possible modules it may use...

@Subcomponent(modules = { Module1.class, Module2.class }) public interface MyBaseActivityComponent { public void inject(MyBaseActivity activity); }

所以，现在我可以做这样的事情...

So now I can do something like this...

public abstract class MyBaseActivity extends Activity { private MyBaseActivityComponent component; protected void onCreate(Bundle savedInstanceState) { component = ((MyApp) getApplication())ponent().plus(new Module1(), new Module2()); component.inject(this); } }

但现在我有一个问题，即注入将注入依赖于MyBaseActivity但不是它的子类。建议？

But now I have a problem where the injection will inject dependencies for MyBaseActivity but not it's subclasses. Suggestions?

推荐答案

从理论上讲，你能做到这样。

Theoretically, you can do it like this.

1）指定的子范围

@Scope @Retention(RUNTIME) public @interface PerActivity { }

2。）指定的父组件

2.) Specify the parent component

@Singleton @Component(modules={Module1.class, Module2.class) public interface MyApplicationComponent { Dependency1 providesDependency1(); Dependency2 providesDependency2(); }

3。）指定的子组件

3.) Specify the child component

@PerActivity @Component(dependencies={MyApplicationComponent.class}, modules={Module3.class}) public interface MyBaseActivityComponent extends MyApplicationComponent { void inject(BaseActivity baseActivity); Dependency3 providesDependency3(); }

4。）创建你的模块

4.) Create your module

@Module public class Module3 { @Provides @PerActivity public Dependency3 providesDependency3() { return new Dependency3(); } }

5。）创建活动级别范围的组件

5.) Create Activity-level scoped component

public class BaseActivity extends AppCompatActivity { private MyBaseActivityComponent baseComponent; @Override public void onCreate(Bundle saveState) { super.onCreate(saveState); baseComponent = DaggerBaseActivityComponent.builder() .applicationComponent(((MyApp)getApplication())ponent()) .build(); } public MyBaseActivityComponent baseComponent() { return baseComponent; } @Override public void onDestroy() { component = null; super.onDestroy(); } }

请回复，如果它的工作，previously我忘了指定在我的组件的依赖关系，并得到了编译错误，但它应该像这样工作。

Please reply if it worked, previously I forgot to specify the dependencies in my Component and got compile errors, but it should work like this.

另外，如果你需要指定一个子组件每个活动，那么你可以指定与在 BaseActivityComponent 部分...

Also, if you need to specify a subcomponent for each Activity, then you can just specify the dependencies with provision methods in the BaseActivityComponent component...

@PerActivity @Component(dependencies={MyBaseActivityComponent.class}, modules={Module4.class}) public interface MyActivityComponent extends MyBaseActivityComponent { public void inject(MyActivity myActivity); Dependency4 providesDependency4(); } @Module public class Module4 { @PerActivity @Provides public Dependency4 providesDependency4(Dependency3 dependency3) { return new Dependency4(dependency3); } } public class MyActivity extends MyBaseActivity { private MyActivityComponent component; @Override public void onCreate(Bundle saveInstanceState) { super.onCreate(saveInstanceState); component = DaggerMyActivityComponent.builder() .applicationComponent(((MyApp)getApplication())ponent()) .myBaseActivityComponent(baseComponent()) .build(); } @Override public void onDestroy() { component = null; super.onDestroy(); } }

修改： @Subcomponent 工程与子工厂方法根据的的文档只有当您使用以下方式（即，使用条款/工厂方法嵌入父组件中的子组件定义）：

EDIT: @Subcomponent works to replace component dependencies with subcomponent factory methods according to the docs only if you use the following pattern (aka, embedding the subcomponent within the parent component using a provision/factory method definition):

@Singleton @Component interface ApplicationComponent { // component methods... RequestComponent newRequestComponent(RequestModule requestModule); }

其中，

@Subcomponent(modules={RequestModule.class}) interface RequestComponent { RequestSomething requestSomething(); }