使用MediaBrowserCompat.Mediaitem收集媒体项目

Question

我当前获取所有Musik文件的方法是使用内容解析器和游标。现在，我已经阅读了更好的方法。我尝试使用 import pandas as pd df1 = pd.read_excel('/.../dummy_data_examples.xlsx', sheet_name='Sheet1') df2 = pd.read_excel('/.../refdata_examples.xlsx', sheet_name='Sheet1') df1['price'] = df1.apply(lambda row:df2.loc[process.extract(row.Defproduto, df2['Defproduto'],limit=1,scorer=fuzz.ratio)[0][2],].price,axis=1) ，但显然没有得到正确的输出？我的MediaBrowserCompat.MediaItem函数是错误的还是在“主要活动”中将其称为错误？

主要活动：

onLoadChildren

服务：

package com.name.mediabrowsertest

    import android.content.ComponentName
    import android.content.Context
    import android.content.res.Configuration
    import android.media.AudioManager
    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.media.MediaBrowserCompat
    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(){
            var mMediaItems = mMediaBrowser.subscribe(mMediaBrowser.root,object: MediaBrowserCompat.SubscriptionCallback(){})


            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){
                        MediaControllerCompat.getMediaController(this@MainActivity).transportControls.pause()
                    }else{
                        var test = MediaBrowserCompat.MediaItem.CONTENTS_FILE_DESCRIPTOR
                        Log.i("TEST",test.toString())
                        MediaControllerCompat.getMediaController(this@MainActivity).transportControls.playFromMediaId(MediaBrowserCompat.EXTRA_MEDIA_ID,null)
                        MediaControllerCompat.getMediaController(this@MainActivity).transportControls.play()

                        //MediaControllerCompat.getMediaController(this@MainActivity).transportControls.playFromMediaId()
                        Log.i("TEST","TEST")

                    }
                }
            })
            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")
            //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()
        }

    }