特点

Hilt就是Android团队联系了Dagger2团队,一起开发出来的一个专门面向Android的依赖注入框架。

相比于Dagger2,Hilt最明显的特征就是:

  1. 简单。
  2. 提供了Android专属的API。

Hilt做的优化包括:

  1. 无需编写大量的Component代码
  2. Scope也会与Component自动绑定
  3. 预定义绑定,例如 Application与Activity
  4. 预定义的限定符,例如@ApplicationContext与@ActivityContext

基本配置

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classpath 'com.google.dagger:hilt-android-gradle-plugin:2.28-alpha'
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apply plugin: 'dagger.hilt.android.plugin'
//hilt
implementation "com.google.dagger:hilt-android:2.28-alpha"
annotationProcessor "com.google.dagger:hilt-android-compiler:2.28-alpha"
//kotlin
//katp "com.google.dagger:hilt-android-compiler:2.28-alpha"
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//支持java8
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}

Hilt 目前支持以下 Android 类。

Application
Activity
Fragment
View
Service
BroadcastReceiver

基本使用

1. 提供一个对象

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public class HttpObject {
}

2. 编写Module

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@InstallIn(ActivityComponent.class)
@Module
public class HttpModule {
@Provides
public HttpObject getHttpObject(){
return new HttpObject();
}
}

3. 注入到Activity

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@AndroidEntryPoint
public class MainActivity extends AppCompatActivity {
@Inject
HttpObject httpObject;
@Inject
HttpObject httpObject2;

4. Application中注册

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@HiltAndroidApp
public class MyApplication extends Application {

}

5. 全局单例使用

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@InstallIn(ApplicationComponent.class)
@Module
public class HttpModule {

@Provides
@Singleton
public HttpObject getHttpObject(){
return new HttpObject();
}
}

注意:Hilt注入的字段是不可以声明成private

为接口注入实例

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public interface AnalyticsService {
void analyticsMethods();
}
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public class AnalyticsServiceImpl implements AnalyticsService {
...
@Inject
AnalyticsServiceImpl(...) {
...
}
}
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@Module
@InstallIn(ActivityComponent.class)
public abstract class AnalyticsModule {

@Binds
public abstract AnalyticsService bindAnalyticsService(
AnalyticsServiceImpl analyticsServiceImpl
);
}

Component与Scope

Hilt 提供了以下组件:

组件生命周期

同时还提供了相应的作用域

注意事项

实现有使用gradle插件做字节码插桩。
C:\Users\Administrator\.gradle\caches\modules-2\files-2.1\com.google.dagger\hilt-android-gradle-plugin\2.28-alpha\eb33a043b2bbdc7cdee3c851d0f8532bfd3645a5\hilt-android-gradle-plugin-2.28-alpha-sources\dagger\hilt\android\plugin

应用

Hilt网络隔离层设计