我使用ListAdapter作为RecyclerView的源代码，它将显示MVoice的列表。数据源是mHomeViewModel.listVoiceBySort，它是LiveData<List<MVoice>>，你可以看到代码A。
添加记录后，mHomeViewModel.listVoiceBySort.observe将启动，myAdapter.submitList(it)也将启动。
但是我发现，最新的mHomeViewModel.listVoiceBySort没有应用到ListAdapter，你可以看到Log A。
如何在启动submitList后立即刷新ListAdapter的数据源？

日志A

E/My: itemCount: 13 it: 14 CurrentList:13

代码A

binding.recyclerViewVoice.adapter = myAdapter
mHomeViewModel.listVoiceBySort.observe(this.viewLifecycleOwner) {
   myAdapter.submitList(it)
   Log.e("My","itemCount: "+myAdapter.itemCount+ " it: "+it.size+ " CurrentList:"+myAdapter.currentList.size)

}

class VoiceAdapters (private val aHomeViewModel: HomeViewModel, private val mPlay: PlayInterface):
        ListAdapter<MVoice, VoiceAdapters.VoiceViewHolder>(MVoiceDiffCallback()) {

    private lateinit var mContext: Context
    private lateinit var mLifecycleOwner:LifecycleOwner

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): VoiceViewHolder {
        mContext = parent.context
        mLifecycleOwner = mContext as LifecycleOwner

        return VoiceViewHolder(
            LayoutVoiceItemBinding.inflate(LayoutInflater.from(parent.context), parent, false).also {              
               it.lifecycleOwner = mLifecycleOwner
               it.aHomeViewModel = aHomeViewModel
            }
        )
    }

    override fun onBindViewHolder(holder: VoiceViewHolder, position: Int) {
        val inputMVoice = getItem(position)
        holder.bind(inputMVoice)
    }

   
    inner class VoiceViewHolder (private val binding: LayoutVoiceItemBinding):
          RecyclerView.ViewHolder(binding.root) {
       
        fun bind(inputMVoice: MVoice) {                        
            binding.amVoice = inputMVoice          
            binding.executePendingBindings()
        }
    }

}

class MVoiceDiffCallback : DiffUtil.ItemCallback<MVoice>() {
    override fun areItemsTheSame(oldItem: MVoice, newItem: MVoice): Boolean {
        return oldItem.id == newItem.id
    }

    override fun areContentsTheSame(oldItem: MVoice, newItem: MVoice): Boolean {
        return oldItem == newItem
    }
}

新增内容

致天福04：谢谢！
下面的代码B是如何获取LiveDate mHomeViewModel.listVoiceBySort。

代码B

class HomeViewModel(val mApplication: Application, private val mDBVoiceRepository: DBVoiceRepository) : AndroidViewModel(mApplication) {

    private val _listVoiceBySort=_sortBy.switchMap {
        mDBVoiceRepository.listVoiceBySort(it)
    }

    val listVoiceBySort: LiveData<List<MVoice>> =_listVoiceBySort
    ...
}

class DBVoiceRepository private constructor(private val mDBVoiceDao: DBVoiceDao){

    private val _isHaveRecord= MutableLiveData<Boolean>(false)
    val isHaveRecord:LiveData<Boolean> =_isHaveRecord

    fun listVoiceBySort(aSortBy: ESortBy): LiveData<List<MVoice>> {
        var query=when (aSortBy){
            ESortBy.StartPriority ->
               "SELECT * FROM voice_table ORDER BY starred desc, createdDate desc"
            ESortBy.DateDesc ->
               "SELECT * FROM voice_table ORDER BY createdDate desc"
            ESortBy.DateAsc ->
               "SELECT * FROM voice_table ORDER BY createdDate"
            ESortBy.TitleDesc ->
               "SELECT * FROM voice_table ORDER BY title desc"
            ESortBy.TitleAsc ->
               "SELECT * FROM voice_table ORDER BY title"
        }
        return mDBVoiceDao.runtimeQuery(SimpleSQLiteQuery(query)).map {
            _isHaveRecord.value =!it.isNullOrEmpty()
            it
        }
    }
    ...
}

@Dao
interface DBVoiceDao{   
   @RawQuery(observedEntities = [MVoice::class])
   fun  runtimeQuery(sortQuery: SupportSQLiteQuery): LiveData<List<MVoice>>
   ...
}

abstract class DBVoiceDatabase : RoomDatabase() {
   ...
}