本文适宜有肯定的Dagger2应用根底的同学
上一篇:Dagger2多模块我的项目Component组织形式抉择(二)
下一篇:[dagger.android多模块我的项目实现(二)]()
前两篇文章咱们讲了两种多模块我的项目怎么应用Dagger2。
发现在每个Activity的onCreate中都须要调一个inject办法
NewsComponentHolder.newsComponent.inject(this)
UserComponentHolder.userComponent.inject(this)其实还能够用dagger2专给android应用的dagger.android来简化这种操作。
先看一般多模块我的项目
咱们在Dagger2多模块我的项目Component组织形式抉择(一)的根底上革新实现
dagger.android的核心思想是在每个Component收集两个Map
Map<Class<?>, Provider<AndroidInjector.Factory<?>>> injectorFactoriesWithClassKeys
Map<String, Provider<AndroidInjector.Factory<?>>> injectorFactoriesWithStringKeys这两个Map定义在AndroidInjectionModule中
@Beta
@Module
public abstract class AndroidInjectionModule {
@Multibinds
abstract Map<Class<?>, AndroidInjector.Factory<?>> classKeyedInjectorFactories();
@Multibinds
abstract Map<String, AndroidInjector.Factory<?>> stringKeyedInjectorFactories();
private AndroidInjectionModule() {}
}dagger.android会把把收集到的这两个Map注入到DispatchingAndroidInjector中，dagger.android就是通过这个DispatchingAndroidInjector注入到Activity,Fragment中
怎么收集呢
首先定义一个 xxxBindModule ，将要注入的Activity,fragment用@ContributesAndroidInjector注解
dagger.android会把这些收集到后面的Map中去
@Module(includes = [AndroidInjectionModule::class])
abstract class NewsBindModule {
@ContributesAndroidInjector
abstract fun newsActivity(): NewsActivity
}而后相应的Component的modules加上xxxBindModule,
去掉inject(XXXActivity)这样的一大堆申明办法,洁净多了
@NewsScope
@Subcomponent(modules = [NewsModule::class, NewsBindModule::class])
interface NewsComponent {
@Subcomponent.Factory
interface Factory {
fun create(): NewsComponent
}
}之后依照dagger.android用法要让Application实现HasAndroidInjector接口，并注入dispatchingAndroidInjector实例
class AppApplication : BaseApplication(), NewsComponentProvider, UserComponentProvider, HasAndroidInjector {
@Inject
lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
lateinit var appComponent: AppComponent
override fun onCreate() {
super.onCreate()
appComponent = DaggerAppComponent.factory().create(this)
}
override fun provideNewsComponent(): NewsComponent {
return appComponent.newsComponentFactory().create()
}
override fun provideUserComponent(): UserComponent {
return appComponent.userComponentFactory().create()
}
override fun androidInjector(): AndroidInjector<Any> {
return dispatchingAndroidInjector
}
}再在Component加上一个注入到下面Appliction的办法(因为news模块拿不到AppApplication的援用，间接注入到Any好了)
@NewsScope
@Subcomponent(modules = [NewsModule::class, NewsBindModule::class])
interface NewsComponent {
@Subcomponent.Factory
interface Factory {
fun create(): NewsComponent
}
fun inject(any: Any)
}而后在AppApplication中注入
class AppApplication : BaseApplication(), NewsComponentProvider, UserComponentProvider {
@Inject
lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
lateinit var appComponent: AppComponent
override fun onCreate() {
super.onCreate()
appComponent = DaggerAppComponent.factory().create(this)
NewsComponentHolder.newsComponent.inject(this)
}
override fun provideNewsComponent(): NewsComponent {
return appComponent.newsComponentFactory().create()
}
override fun provideUserComponent(): UserComponent {
return appComponent.userComponentFactory().create()
}
override fun androidInjector(): AndroidInjector<Any> {
return dispatchingAndroidInjector
}
}最初在Activity，fragment的onCreate办法中退出AndroidInjection.inject(this),留神要放在super.onCreate(savedInstanceState)后面,咱们把这一步放在BaseActivity,BaseFragment里
open class BaseActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
AndroidInjection.inject(this)
super.onCreate(savedInstanceState)
}
}而后Activity只有继承BaseActivity就能够了，不须要写任何注入代码了，像平时应用一样了，想要注入对象的变量加 @Inject就能够了
class NewsActivity : BaseActivity() {
@Inject
lateinit var set: Set<String>
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_news)
text.text = set.toString()
}
}这种写法对于单模块我的项目没有问题，然而对多模块我的项目来说这有问题了，下面咱们只注入了news模块的，user模块的没有。咱们有多个Component,然而这里只有一个dispatchingAndroidInjector，你用哪个Component注入都不全，前面注入的会笼罩后面注入的。所以这里要革新下
从后面咱们晓得一个Component最终生成一个DispatchingAndroidInjector，多个Component咱们把它们都收集起来
咱们先定义一个BaseDispatchingInjector,它相当于后面的AppApplication,接管一个Component注入的DispatchingAndroidInjector
class BaseDispatchingInjector {
@Inject
lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
}而后把每个Component里的inject(any: Any)改成inject(baseDispatchingInjector: BaseDispatchingInjector)
@NewsScope
@Subcomponent(modules = [NewsModule::class, NewsBindModule::class])
interface NewsComponent {
@Subcomponent.Factory
interface Factory {
fun create(): NewsComponent
}
fun inject(baseDispatchingInjector: BaseDispatchingInjector)
}
@UserScope
@Subcomponent(modules = [UserModule::class, UserBindModule::class])
interface UserComponent {
@Subcomponent.Factory
interface Factory {
fun create(): UserComponent
}
fun inject(baseDispatchingInjector: BaseDispatchingInjector)
}这样注入
val userDispatchingInjector = BaseDispatchingInjector()
UserComponentHolder.userComponent.inject(userDispatchingInjector)
val newsDispatchingInjector = BaseDispatchingInjector()
NewsComponentHolder.newsComponent.inject(newsDispatchingInjector)这样咱们每个模块都失去一个BaseDispatchingInjector,并且外面每个Activity,Fragment对应的Map都注入好了
而后就要定义一个MultiModuleAndroidInjector把每个模块的BaseDispatchingInjector整合到一起成为一个独自的AndroidInjector
class MultiModuleAndroidInjector : AndroidInjector<Any> {
private val injectors = mutableListOf<BaseDispatchingInjector>()
fun addInjector(injector: HasDispatchingInjector) {
injectors.add(injector)
}
override fun inject(instance: Any) {
val wasInjected = injectors.any { it.dispatchingAndroidInjector.maybeInject(instance) }
if (!wasInjected) {
throw IllegalArgumentException("injection failed")
}
}
}这个MultiModuleAndroidInjector在注入的时候会每个BaseDispatchingInjector都去尝试看能不能注入，这样就把所有Component的注解都遍历了
看AppApplication最初实现
class AppApplication : BaseApplication(), NewsComponentProvider, UserComponentProvider,
HasAndroidInjector {
lateinit var appComponent: AppComponent
private val multiModuleAndroidInjector = MultiModuleAndroidInjector()
override fun onCreate() {
super.onCreate()
appComponent = DaggerAppComponent.factory().create(this)
val userDispatchingInjector = BaseDispatchingInjector()
UserComponentHolder.userComponent.inject(userDispatchingInjector)
multiModuleAndroidInjector.addInjector(userDispatchingInjector)
val newsDispatchingInjector = BaseDispatchingInjector()
NewsComponentHolder.newsComponent.inject(newsDispatchingInjector)
multiModuleAndroidInjector.addInjector(newsDispatchingInjector)
}
override fun provideNewsComponent(): NewsComponent {
return appComponent.newsComponentFactory().create()
}
override fun provideUserComponent(): UserComponent {
return appComponent.userComponentFactory().create()
}
override fun androidInjector(): AndroidInjector<Any> {
return multiModuleAndroidInjector
}
}代码地址
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