入门教程(推荐):
https://www.jianshu.com/p/26d9f99ea3bb
dagger2在Android中的应用
- 添加依赖
implementation 'com.google.dagger:dagger:2.17'
annotationProcessor 'com.google.dagger:dagger-compiler:2.17'
- AppComponent
如果有SubComponent, 为SubComponent提供相应Builder
@Singleton
@Component(modules = {AppModule.class})
public interface AppComponent {
void inject(App app);
MainActivityComponent.Builder getMainActivityComponent();
}
- MainActivityComponent
@ActivityScope
@Subcomponent(modules = SubModule.class)
public interface MainActivityComponent{
void inject(MainActivity main);
@Subcomponent.Builder
interface Builder{
MainActivityComponent build();
}
}
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@Module
public class SubModule {
@ActivityScope
@Provides
public ActivityEntity provideActivityEntity(){
return new ActivityEntity();
}
}
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public class ActivityEntity {
String name = "injectEntity";
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
- AppModule 提供注入的依赖的对象, 经测试, Module中不设置subComponent也没事儿, 只要AppComponent中返回相应的Builder就可以
@Module
public class AppModule {
@Singleton
@Provides
public OkHttp provideOkhttp(){
return new OkHttp();
}
@Singleton
@Provides
public RetrofitClient provideRetrofit(OkHttp okHttp){
return new RetrofitClient(okHttp);
}
}
-----------------------------------------------------------------------------------------------
public class OkHttp {
String name = "okhttp";
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
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public class RetrofitClient {
public String name = "retrofit";
public OkHttp okHttp;
public RetrofitClient(OkHttp okHttp) {
this.okHttp = okHttp;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
- App
public class App extends Application {
private static AppComponent appComponent;
@Override
public void onCreate() {
super.onCreate();
appComponent = DaggerAppComponent.builder().appModule(new AppModule()).build();
appComponent.inject(this);
}
public static AppComponent getAppComponent() {
return appComponent;
}
}
- MainActivity
public class MainActivity extends BaseActivity {
private static final String TAG = "MainActivity";
@Inject
RetrofitClient client;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
App.getAppComponent().getMainActivityComponent().build().inject(this);
Log.e(TAG, client.getName() );
Log.e(TAG, client.okHttp.getName() );
Log.e(TAG, String.valueOf(client.hashCode()));
}
}
dagger.android在Android中的应用
- 添加依赖
implementation 'com.google.dagger:dagger-android:2.17'
implementation 'com.google.dagger:dagger-android-support:2.17'
annotationProcessor 'com.google.dagger:dagger-android-processor:2.17'
- AppComponent
modules中添加 AndroidInjectionModule.class
@Singleton
@Component(modules = {AppModule.class, AndroidInjectionModule.class, AppBindModule.class})
public interface AppComponent {
void inject(App app);
}
- MainActivityComponent
- 类继承AndroidInjector
- Builder extends AndroidInjector.Builder
- 类继承AndroidInjector
@ActivityScope
@Subcomponent(modules = SubModule.class)
public interface MainActivityComponent extends AndroidInjector{
@Subcomponent.Builder
abstract class Builder extends AndroidInjector.Builder {}
}
- SecondActivityComponent
@ActivityScope
@Subcomponent
public interface SecondActivityComponent extends AndroidInjector{
@Subcomponent.Builder
abstract class Builder extends AndroidInjector.Builder {}
}
- AppModule 提供注入的对象
@Module
public class AppModule {
@Singleton
@Provides
public OkHttp provideOkhttp(){
return new OkHttp();
}
@Singleton
@Provides
public RetrofitClient provideRetrofit(OkHttp okHttp){
return new RetrofitClient(okHttp);
}
}
- AppBindModule 负责绑定SubComponent, 如果新增了Activity只需要修改此处即可.
@Module
public abstract class AppBindModule {
@ContributesAndroidInjector
abstract MainActivity contributeMainActivity();
@ContributesAndroidInjector
abstract SecondActivity contributeSecondActivity();
}
- App
- implements HasActivityInjector
- 注入DispatchingAndroidInjector
并返回 - onCreate中实现注入逻辑
public class App extends Application implements HasActivityInjector {
@Inject
DispatchingAndroidInjector androidInjector;
@Override
public void onCreate() {
super.onCreate();
DaggerAppComponent.builder().appModule(new AppModule()).build().inject(this);
}
@Override
public AndroidInjector activityInjector() {
return androidInjector;
}
}
- BaseActivity
在super前调用 AndroidInjection.inject(this);
public class BaseActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
AndroidInjection.inject(this);
super.onCreate(savedInstanceState);
}
}
- 继承自BaseActivity的相应Activity
public class SecondActivity extends BaseActivity {
private static final String TAG = "SecondActivity";
@Inject
RetrofitClient client;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
Log.e(TAG, client.getName() );
Log.e(TAG, client.okHttp.getName() );
Log.e(TAG, String.valueOf(client.hashCode()));
}
}
注意
- 如果AppBindModule中是这种传统的方式的话, AppComponent中需要分别获得相应的Builder
@Module
public abstract class AppBindModule {
@Binds
@IntoMap
@ActivityKey(MainActivity.class)
abstract AndroidInjector.Factory bindAndroidInjector( MainActivityComponent.Builder builder);
@Binds
@IntoMap
@ActivityKey(SecondActivity.class)
abstract AndroidInjector.Factory bindAndroidInjector2(SecondComponent.Builder builder);
}
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@Singleton
@Component(modules = {AppModule.class, AndroidInjectionModule.class, AppBindModule.class})
public interface AppComponent {
void inject(App app);
MainActivityComponent.Builder getMainActivityComponent();
SecondComponent.Builder getSecondComponent();
}