我尝试了不同的方法，但遗憾的是它们都没有起作用。我可以收集我的音乐文件，但在这一点上，我尝试不播放它们。我试图在MainActivity中获取音乐文件，但不确定如何从“ mMediaBrowser”变量中获取音乐文件。我使用已知的MediaID进行了进一步尝试，但是当我按下按钮时没有任何反应。谁能帮我？
MainActivity：
package com.name.mediabrowsertest
import android.Manifest
import android.content.ComponentName
import android.content.Context
import android.content.pm.PackageManager
import android.content.res.Configuration
import android.media.AudioManager
import android.media.MediaDataSource
import android.media.session.MediaController
import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.provider.MediaStore
import android.support.annotation.RequiresApi
import android.support.v4.app.ActivityCompat
import android.support.v4.content.ContextCompat
import android.support.v4.media.MediaBrowserCompat
import android.support.v4.media.MediaBrowserServiceCompat
import android.support.v4.media.MediaMetadataCompat
import android.support.v4.media.session.MediaControllerCompat
import android.support.v4.media.session.PlaybackStateCompat
import android.util.Log
import android.view.View
import android.widget.ImageView
class MainActivity : AppCompatActivity() {
private lateinit var mMediaBrowser: MediaBrowserCompat
fun buildTransportControls(){
mMediaBrowser.subscribe(mMediaBrowser.root,object: MediaBrowserCompat.SubscriptionCallback(){})
//mMediaBrowser.getItem("")
Log.i("EXTRAS",mMediaBrowser.extras.toString())
var mPlayPause = findViewById<ImageView>(R.id.imageView)
//Attach listen to button
mPlayPause.setOnClickListener(object: View.OnClickListener {
override fun onClick(v : View ){
var pbSate = MediaControllerCompat.getMediaController(this@MainActivity).playbackState.playbackState
if(pbSate == PlaybackStateCompat.STATE_PLAYING){
Log.i("1","11111")
MediaControllerCompat.getMediaController(this@MainActivity).transportControls.pause()
}else{
Log.i("1","22222")
MediaControllerCompat.getMediaController(this@MainActivity).transportControls.playFromMediaId("Böug",null)
MediaControllerCompat.getMediaController(this@MainActivity).transportControls.play()
//MediaControllerCompat.getMediaController(this@MainActivity).transportControls.playFromMediaId()
}
}
})
var mediaController = MediaControllerCompat.getMediaController(this@MainActivity)
//Show Init state
var metadat = mediaController.metadata
var pbState = mediaController.playbackState
//Register Callback to stay synced
mediaController.registerCallback(controllerCallback)
}
val controllerCallback = object : MediaControllerCompat.Callback() {
override fun onMetadataChanged(metadat:MediaMetadataCompat){
Log.i("Musik",metadat.toString())
}
override fun onPlaybackStateChanged(state :PlaybackStateCompat){}
}
private val mConnectionCallbacks = object : MediaBrowserCompat.ConnectionCallback() {
override fun onConnected() {
Log.i("Connection","Connecting")
// Get the token for the MediaSession
val token = mMediaBrowser.sessionToken
// Create a MediaControllerCompat
val mediaController = MediaControllerCompat(this@MainActivity,token)
// Save the controller
MediaControllerCompat.setMediaController(this@MainActivity, mediaController)
// Finish building the UI
buildTransportControls()
}
override fun onConnectionSuspended() {
// The Service has crashed. Disable transport controls until it automatically reconnects
Log.i("ERROR","Connection Suspended")
}
override fun onConnectionFailed() {
// The Service has refused our connection
Log.i("ERROR","Connection Failed")
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
Log.i("Hello World","Hello")
permissionRequest()
if(ContextCompat.checkSelfPermission(this,Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED){
//Create MediaBrowser Service
mMediaBrowser = MediaBrowserCompat(this,
ComponentName(this, MediaPlaybackService::class.java),
mConnectionCallbacks,
null)
}
Log.i("Hello World","Hello2")
}
override fun onStart() {
super.onStart()
mMediaBrowser.connect()
}
override fun onResume() {
super.onResume()
volumeControlStream = AudioManager.STREAM_MUSIC
}
override fun onStop() {
super.onStop()
if(MediaControllerCompat.getMediaController(this@MainActivity) != null){
MediaControllerCompat.getMediaController(this@MainActivity).unregisterCallback(controllerCallback)
}
mMediaBrowser.disconnect()
}
fun permissionRequest(){
val permissions = ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
if(permissions != PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(this, arrayOf(
Manifest.permission.READ_EXTERNAL_STORAGE
),101)
}
}
}
服务：
package com.name.mediabrowsertest
import android.media.MediaDescription
import android.media.MediaMetadata
import android.media.browse.MediaBrowser
import android.media.session.MediaSession
import android.os.Build
import android.os.Bundle
import android.provider.MediaStore
import android.support.annotation.RequiresApi
import android.support.v4.media.MediaBrowserCompat
import android.support.v4.media.MediaBrowserServiceCompat
import android.support.v4.media.MediaDescriptionCompat
import android.support.v4.media.MediaMetadataCompat
import android.support.v4.media.session.MediaSessionCompat
import android.support.v4.media.session.PlaybackStateCompat
import android.util.Log
import com.name.mediabrowsertest.Services.contentcatalogs.MusicLibrary
class MediaPlaybackService: MediaBrowserServiceCompat(){
//private val MY_MEDIA_ROOT_ID = "MediaStore.Audio.Media.EXTERNAL_CONTENT_URI"
private val MY_MEDIA_ROOT_ID ="root"
private lateinit var mMediaSession: MediaSessionCompat
private lateinit var mStateBuilder : PlaybackStateCompat.Builder
private var MySessionCallback =object : MediaSessionCompat.Callback() {
override fun onPause() {
super.onPause()
}
override fun onPlay() {
super.onPlay()
}
}
override fun onCreate() {
super.onCreate()
//Create the MediaSession
mMediaSession = MediaSessionCompat(this,"PLAYER")
//Setting the necessary Flags (Media Buttons)
mMediaSession.setFlags(
MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS or MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS)
//Set an inital PlaybackStatewith ACTION_BUTTONS, so Media buttons can start the player
mStateBuilder = PlaybackStateCompat.Builder().setActions(
PlaybackStateCompat.ACTION_PLAY or PlaybackStateCompat.ACTION_PAUSE)
//Set our PLaybackState for the MediaSession
mMediaSession.setPlaybackState(mStateBuilder.build())
//Handles callbacks from Media Controller MySessionCalback is a PlaeHolder
mMediaSession.setCallback(MySessionCallback)
//Set SessionToken so Activites can communicate with it
sessionToken = mMediaSession.sessionToken
}
override fun onLoadChildren(parentId: String, result: Result<MutableList<MediaBrowserCompat.MediaItem>>) {
var mediaItems:ArrayList<MediaBrowserCompat.MediaItem> = ArrayList()
var albums = MusicLibrary(this@MediaPlaybackService).getMusic()
for(item in MusicLibrary.MusicFiles){
val songList = MediaBrowserCompat.MediaItem(item,
MediaBrowserCompat.MediaItem.FLAG_PLAYABLE)
mediaItems.add(songList)
}
Log.i("MEDIA_ITEMS",mediaItems.toString())
result.sendResult(mediaItems)
}
override fun onGetRoot(clientPackageName: String, clientUid: Int, rootHints: Bundle?): BrowserRoot? {
return BrowserRoot(MY_MEDIA_ROOT_ID,null)
}
}
如果需要，可以使用contentListener：
package com.name.mediabrowsertest.Services.contentcatalogs
import android.annotation.SuppressLint
import android.content.ContentUris
import android.content.Context
import android.database.Cursor
import android.graphics.drawable.Drawable
import android.net.Uri
import android.provider.MediaStore
import android.support.v4.media.MediaDescriptionCompat
import android.util.Log
import com.name.mediabrowsertest.R
import java.io.FileNotFoundException
class MusicLibrary(val context: Context) {
companion object {
lateinit var albums: ArrayList<String>
var MusicFiles = arrayListOf<MediaDescriptionCompat>()
}
var desc= arrayListOf<MediaDescriptionCompat>()
var music_Artist = arrayListOf<String>()
var music_CoverID = arrayListOf<Drawable>()
var music_Duration = arrayListOf<Int>()
var album_Title = arrayListOf<String>()
@SuppressLint("NewApi")
fun getMusic() {
val contentResolver = context.contentResolver
var songUri: Uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
var songCursor: Cursor = contentResolver.query(songUri, null, null, null, null)
//Defining the Uri for the Album covers
val artworkUri = Uri.parse("content://media/external/audio/albumart")
var albumArtUri: Uri
var albumDrawable: Drawable
if (songCursor != null && songCursor.moveToFirst()) {
//Getting the Position of the stored values
var albumCoverId: Int = songCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID)
var songDuration = songCursor.getColumnIndex(MediaStore.Audio.Media.DURATION)
var albumTitle = songCursor.getColumnIndex(MediaStore.Audio.AlbumColumns.ALBUM)
do {
//Ensure that atleast on Element is in album_Title
if(!album_Title.isEmpty()) {
//Test if album is already in array
if(album_Title.contains(songCursor.getString(albumTitle))) {
//If album is already in Array skip loop
continue
}
}
album_Title.add(songCursor.getString(albumTitle))
//getting the Uri of the Album
albumArtUri = ContentUris.withAppendedId(artworkUri, songCursor.getLong(albumCoverId))
//Try to get the Album cover and catch if fail
try {
var imageInputStream = context.contentResolver.openInputStream(albumArtUri)
albumDrawable = Drawable.createFromStream(imageInputStream, albumArtUri.toString())
} catch (e: FileNotFoundException) {
albumDrawable = context.getDrawable(R.drawable.baum)
}
//Add the Values to the Array
music_CoverID.add(albumDrawable)
music_Duration.add((songCursor.getInt(songDuration)) / 1000 * 60)
//Get Location of File
var mediaDescriper = MediaDescriptionCompat.Builder().setMediaId(songCursor.getString(albumCoverId)).setTitle(songCursor.getString(albumTitle)).build()
MusicFiles.add(mediaDescriper)
Log.i("ALBUMNAMES", album_Title.toString())
//Go to the next Cursor Position
} while (songCursor.moveToNext())
//Copy values to Compainon Object
albums = album_Title
Log.i("MUSICLIBRARY",MusicFiles.toString())
}
}
}