android - 不推荐使用 Dagger 2.2 组件构建器模块方法

Question

我开始使用 dagger 2.2，组件构建器中的模块方法已被弃用。

这是我的应用程序组件:

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

以及应用程序模块:

@Module
public class ApplicationModule {
    Application application;

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

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

这是生成的类:

@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;
    }
  }
}

如果不使用 ComponentBuilder，如何初始化组件？

Answer 1

您应该阅读为什么不推荐使用它的描述。 如果您使用的是 IntelliJ 或 Android Studio 等 IDE，您只需选择方法并点击Control + Q 在 Windows 上阅读 Javadoc，包括弃用通知。

Javadoc 内容如下:

@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.

从这个链接你可以看到:

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.

---

可以肯定地说，您可以忽略弃用。它旨在通知您未使用的方法和模块。只要您在子图中的某处实际需要/使用 Application ，就会需要该模块，并且弃用警告将消失。