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我在我的应用程序的活动和片段中创建了多个 MediaBrowserCompat 实例，在这种情况下，每个组件都必须创建 MediaBrowserCompat 并将其连接到服务等等。为了更简单，使用 Dagger 只创建一个 MediaBrowserCompat 实例并将其注入到我想要的任何地方是不是一个坏主意？

像这样：

这是我创建 MediaBrowserCompat 的 MediaBrowserModule

@Module
class MediaBrowserModule {

@Provides
@Singleton
fun providesMediaBrowserCompat(
    context: Context,
    componentName: ComponentName,
    connectionCallback: MediaBrowserConnectionCallback
): MediaBrowserCompat = MediaBrowserCompat(context, componentName, connectionCallback, null)

@Provides
fun providesMediaBrowserServiceComponentName(context: Context): ComponentName =
    ComponentName(context, MediaBrowserService::class.java)

@Provides
@Singleton
fun providesMediaBrowserConnectionStatus(): MutableLiveData<MediaBrowserConnectionCallback.ConnectionStatus> =
    MutableLiveData()
}

MediaBrowser 连接回调实现：

class MediaBrowserConnectionCallback @Inject constructor(private val connectionStatus: MutableLiveData<ConnectionStatus>) :
MediaBrowserCompat.ConnectionCallback() {

override fun onConnected() {
    super.onConnected()
    connectionStatus.postValue(ConnectionStatus.Connected)
}

override fun onConnectionSuspended() {
    super.onConnectionSuspended()
    connectionStatus.postValue(ConnectionStatus.Suspended)
}

override fun onConnectionFailed() {
    super.onConnectionFailed()
    connectionStatus.postValue(ConnectionStatus.Failed)
}

enum class ConnectionStatus {
    Connected, Suspended, Failed
}
}

最后，我可以在任何地方使用它，如下所示：

class MainActivity : DaggerAppCompatActivity(), Observer<MediaBrowserConnectionCallback.ConnectionStatus> {

@Inject
lateinit var connectionState: MutableLiveData<MediaBrowserConnectionCallback.ConnectionStatus>
@Inject
lateinit var mediaBrowserCompat: MediaBrowserCompat

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    connectionState.observe(this, this)
}

override fun onStart() {
    super.onStart()
    if (!mediaBrowserCompat.isConnected)
        mediaBrowserCompat.connect()
}

override fun onChanged(status: MediaBrowserConnectionCallback.ConnectionStatus?) {
    Toast.makeText(this, status?.name, Toast.LENGTH_LONG).show()
   }
}

谢谢。

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