Dagger 2.2组件生成器模块方法已不推荐

我开始使用匕首2.2，不推荐使用 Component 构建器中的模块方法。

这是我的应用程序组件:

@Component(modules = ApplicationModule.class)
public interface ApplicationComponent {
void inject(Application application);
}

应用程序模块:

@Module
public class ApplicationModule {
Application application;


public ApplicationModule(Application application) {
this.application = application;
}


@Provides
@Singleton
Application providesApplication() {
return application;
}
}

下面是生成的类:

@Generated(
value = "dagger.internal.codegen.ComponentProcessor",
comments = "https://google.github.io/dagger"
)
public final class DaggerApplicationComponent implements ApplicationComponent {
private DaggerApplicationComponent(Builder builder) {
assert builder != null;
}


public static Builder builder() {
return new Builder();
}


public static ApplicationComponent create() {
return builder().build();
}


@Override
public void inject(Application application) {
MembersInjectors.<Application>noOp().injectMembers(application);
}


public static final class Builder {
private Builder() {}


public ApplicationComponent build() {
return new DaggerApplicationComponent(this);
}


/**
* @deprecated This module is declared, but an instance is not used in the component. This method is a no-op. For more, see https://google.github.io/dagger/unused-modules.
*/
@Deprecated
public Builder applicationModule(ApplicationModule applicationModule) {
Preconditions.checkNotNull(applicationModule);
return this;
}
}
}

如果没有组件生成器，我如何初始化组件？

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小开
最佳答案

You should read the description of why it is deprecated. If you are using an IDE like IntelliJ or Android Studio you can just select the method and hit Control + Q on Windows to read the Javadoc including the deprecation notice.

The Javadoc reads:

@deprecated This module is declared, but an instance is not used in the component. This method is a no-op. For more, see https://google.github.io/dagger/unused-modules.

And from this link you can see:

When the Dagger processor generates components, it only requires instances of modules and component dependencies that are explicitly needed to supply requests for a binding.

  • If all of a module’s methods that are used in the component are static, Dagger does not need an instance of that module at all. Dagger can invoke the static methods directly without a module.
  • If a module provides no bindings for a Component, no instance of that module is necessary to construct the graph.

It is safe to say that you can just ignore the deprecation. It is intended to notify you of unused methods and modules. As soon as you actually require / use Application somewhere in your subgraph the module is going to be needed, and the deprecation warning will go away.

小开

I have the same problem with host and I just want everyone has deprecated issue on Generated component builder class should check two things to save time:

1/ Correct dagger syntax for module, component also check carefully where you inject.

2/ Must have injection object (inject annotation and its object) in place you want to inject or else the dagger compiler cannot see where to use your module so some method will be deprecated.Just inject at least one module's provides to your injection place and re-compile the code, you won't have that issue anymore :)

小开

It show deprecated because you are not using Component and module in your application by 

@Inject
SomeObjectFromModule mSomeObject

if you are not injecting dependencies in your applications there is no use of initialising your component so dagger look for at least one usage

once you add these lines in any classes you want to inject views and then clean build and rebuild the project and your deprecation will be solved

小开

It showing error when my Module have no @Provides method or the object that provide by Dagger is not used in app.
Example to remove deprecated module

Module

@Module
public class SecondActivityModule {
@Provides
Book provideBookTest() {
return new Book();
}
}

Activity

public class SecondActivity extends AppCompatActivity {
@Inject
Book test;
...
}

OR in Component

@Component(modules = SecondModule.class)
public interface SecondComponent {


void inject(SecondActivity activity);


Book getBookTest();
}
小开

you will get module method deprecated if you declare void inject(AppCompactActivity activity); in component class. instead of you have to use tight coupling like following void inject(MainActivity activity);and rebuild your project you will see, there is no deprecate method in module class


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