我一直在尝试将 Activity 注入(inject)到 ViewUtils 类中,但没有成功。我关注了几篇不同的帖子,但我似乎无法理解我在实现过程中遗漏了什么。
我知道这可能是下面帖子的重复,对此我深表歉意,但老实说,我看不出我错过了什么。这些是我找到的帖子:
- Dagger 2.10 Android subcomponents and builders
- How to create custom scoped modules in dagger 2.10
- https://google.github.io/dagger/subcomponents.html
我的实现如下:
应用组件
@Component(modules = {
AppModule.class, AndroidSupportInjectionModule.class, ActivityBindingModule.class
}) @Singleton public interface AppComponent extends AndroidInjector<EmblyApp> {
@Component.Builder abstract class Builder extends AndroidInjector.Builder<EmblyApp> {}
}
ActivityBindingModule
@Module public abstract class ActivityBindingModule {
@ContributesAndroidInjector
abstract LoginActivity loginActivity();
}
登录子组件
@Subcomponent(modules = LoginSubcomponent.LoginActivityModule.class)
public interface LoginSubcomponent extends AndroidInjector<LoginActivity> {
@Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {}
@Module abstract class LoginActivityModule {
@Binds abstract Activity bindActivity(LoginActivity activity);
@Provides @ActivityScope static ViewUtils viewUtils(Activity activity) {
return new ViewUtils(activity);
}
}
}
ViewUtils
public class ViewUtils {
private final Activity activity;
@Inject public ViewUtils(Activity activity) {
this.activity = activity;
}
}
我得到的错误是:
Error:(14, 22) error: [dagger.android.AndroidInjector.inject(T)] android.app.Activity cannot be provided without an @Inject constructor or from an @Provides-annotated method.
android.app.Activity is injected at
com.emblyapp.app.ui.helpers.ViewUtils.<init>(activity)
com.emblyapp.app.ui.helpers.ViewUtils is injected at
com.emblyapp.app.ui.authentication.login.LoginActivity.viewUtils
com.emblyapp.app.ui.authentication.login.LoginActivity is injected at
dagger.android.AndroidInjector.inject(arg0)
这里有什么问题?感谢您的帮助!
编辑:我忘了说我的 LoginActivity 有 AndroidInjection 注入(inject)
@Override protected void onCreate(Bundle savedInstanceState) {
AndroidInjection.inject(this);
super.onCreate(savedInstanceState);
}
最佳答案
如 dagger android documentation 中所述:
Pro-tip: If your subcomponent and its builder have no other methods or supertypes than the ones mentioned in step #2, you can use @ContributesAndroidInjector to generate them for you. Instead of steps 2 and 3, add an abstract module method that returns your activity, annotate it with @ContributesAndroidInjector, and specify the modules you want to install into the subcomponent. If the subcomponent needs scopes, apply the scope annotations to the method as well.
因此,我们可以摆脱 LoginSubcomponent
并在 ActivityBindingModule
中执行以下更改:
@Module
public abstract class ActivityBindingModule {
@ActivityScope
@ContributesAndroidInjector(modules = LoginActivityModule.class)
abstract LoginActivity loginActivity();
}
LoginActivityModule.java
@Module
abstract class LoginActivityModule {
@Binds
abstract Activity bindActivity(LoginActivity activity);
@Provides
@ActivityScope
static ViewUtils viewUtils(Activity activity) {
return new ViewUtils(activity);
}
}
您的自定义应用程序类:
public class MyApp extends DaggerApplication {
@Inject
DispatchingAndroidInjector dispatchingActivityInjector;
@Override
protected AndroidInjector applicationInjector() {
return DaggerAppComponent.builder().create(this);
}
}
关于android - Dagger 2.10/2.11 注入(inject) Activity 失败,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43865570/