Android点击标题崩溃：无法创建SongViewModel实例求助

开发者阿泽

2026-8-23

Dagger Hilt + ExoPlayer 应用崩溃问题：无法创建SongViewModel实例

点击标题时应用崩溃，Logcat报错Cannot create an instance of class SongViewModel，原因是该类没有无参构造函数。

报错触发位置：

SongFragment代码

@AndroidEntryPoint
class SongFragments : Fragment(R.layout.fragment_song) {

    @Inject
    lateinit var glide: RequestManager

    private lateinit var mainViewModel: MainViewModel

    private val songViewModel: SongViewModel by viewModels()


    private var curplayingSong: sound? = null

    private var playbackState: PlaybackStateCompat? = null

    private var shouldUpdateSeekbar = true

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        mainViewModel = ViewModelProvider(requireActivity()).get(MainViewModel::class.java)
        subscribeToObservers()


        ivPlayPauseDetail.setOnClickListener {
            curplayingSong?.let {
                mainViewModel.playOrToggleSound(it, true)
            }
        }

       seekBar.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {
           override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
               if (fromUser) {
                   setCurPlayerTimeToTextView(progress.toLong())
               }
           }

           override fun onStartTrackingTouch(seekBar: SeekBar?) {
              shouldUpdateSeekbar = false

           }

           override fun onStopTrackingTouch(seekBar: SeekBar?) {
              seekBar?.let {
                  mainViewModel.seekTo(it.progress.toLong())
                  shouldUpdateSeekbar = true
              }
           }

       })

        ivSkipPrevious.setOnClickListener {
            mainViewModel.skipToPreviousSound()
        }
        ivSkip.setOnClickListener{
            mainViewModel.skipToNextSound()
        }
    }



    private fun updateTitleAndSongImage(sound: sound) {
        val title = "${sound.title} - ${sound.subtitle}"
        tvSongName.text = title
        glide.load(sound.imageUrl).into(ivSongImage)
    }

    private fun subscribeToObservers() {
        mainViewModel.mediaItems.observe(viewLifecycleOwner){
            it?.let { result ->
                when(result.status){
                    Status.SUCCESS -> {
                       result.data?.let { sounds ->
                           if (curplayingSong == null && sounds.isNotEmpty()) {
                               curplayingSong = sounds[0]
                               updateTitleAndSongImage(sounds[0])
                           }
                       }
                    }
                    else -> Unit
                }
            }
        }
     mainViewModel.curPlayingSound.observe(viewLifecycleOwner) {
         if(it == null) return@observe
         curplayingSong = it.toSong()
         updateTitleAndSongImage(curplayingSong!!)
     }

        mainViewModel.playbackState.observe(viewLifecycleOwner) {
          playbackState = it
            ivPlayPauseDetail.setImageResource(
                if (playbackState?.isPlaying == true) R.drawable.ic_pause else R.drawable.ic_play
            )
            seekBar.progress = it?.position?.toInt() ?: 0
        }

        songViewModel.curPlayerPosition.observe(viewLifecycleOwner) {
           if (shouldUpdateSeekbar) {
               seekBar.progress = it.toInt()
               setCurPlayerTimeToTextView(it)
           }
        }
        songViewModel.curSongDuration.observe(viewLifecycleOwner) {
            seekBar.max = it.toInt()
            val dateFormat = SimpleDateFormat("mm:ss", Locale.getDefault())
            tvSongDuration.text = dateFormat.format(it)
        }

    }

    private fun  setCurPlayerTimeToTextView(ms: Long) {
        val dateFormat = SimpleDateFormat("mm:ss", Locale.getDefault())
        tvCurTime.text = dateFormat.format(ms)
    }


}

SongViewModel代码

class SongViewModel @ViewModelInject constructor(
    musicServiceConnection: MusicServiceConnection
) : ViewModel() {

    private val playbackState = musicServiceConnection.playBackState

    private  val _curSongDuration = MutableLiveData<Long>()
    val curSongDuration: LiveData<Long> = _curSongDuration

    private val _curPlayerPosition = MutableLiveData<Long>()
    val curPlayerPosition: LiveData<Long> = _curPlayerPosition

    init {
        updateCurrentplayerPostion()
    }

    @SuppressLint("NullSafeMutableLiveData")
    private fun updateCurrentplayerPostion() {
        viewModelScope.launch {
            while(true) {
             val pos = playbackState.value?.currentPlaybackPosition
                if(curPlayerPosition.value != pos){
                    _curPlayerPosition.postValue(pos)
                    _curSongDuration.postValue(MusicService.curSoundDuration)
                }
                delay(UPDATE_PLAYER_POSITION_INTERVAL)
            }
        }
    }
}

Logcat错误信息

2022-08-12 19:11:39.122 10888-10983/com.fridayhouse.snoozz E/ion: ioctl c0044901 failed with code -1: Invalid argument
2022-08-12 19:11:39.318 10888-10888/com.fridayhouse.snoozz E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.fridayhouse.snoozz, PID: 10888
    java.lang.RuntimeException: Cannot create an instance of class com.fridayhouse.snoozz.ui.viewmodels.SongViewModel
        at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:204)
        at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:322)
        at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:304)
        at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:175)
        at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:203)
        at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:111)
        at androidx.lifecycle.ViewModelProvider$Factory.create(ViewModelProvider.kt:83)
        at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187)
        at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153)
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:53)
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:35)
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.getSongViewModel(SongFragments.kt:33)
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.subscribeToObservers(SongFragments.kt:121)
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.onViewCreated(SongFragments.kt:45)
        at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3128)
        at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:552)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:261)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1890)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1814)
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1751)
        at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:538)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:233)
        at android.os.Looper.loop(Looper.java:334)
        at android.app.ActivityThread.main(ActivityThread.java:8396)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:582)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1068)
     Caused by: java.lang.InstantiationException: java.lang.Class<com.fridayhouse.snoozz.ui.viewmodels.SongViewModel> has no zero argument constructor
        at java.lang.Class.newInstance(Native Method)
        at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:202)
        at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:322) 
        at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:304) 
        at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:175) 
        at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:203) 
        at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:111) 
        at androidx.lifecycle.ViewModelProvider$Factory.create(ViewModelProvider.kt:83) 
        at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187) 
        at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153) 
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:53) 
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:35) 
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.getSongViewModel(SongFragments.kt:33) 
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.subscribeToObservers(SongFragments.kt:121) 
        at com.fridayhouse.snoozz.ui.fragments.SongFragments.onViewCreated(SongFragments.kt:45) 
        at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3128) 
        at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:552) 
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:261) 
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1890) 
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1814) 
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1751) 
        at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:538) 
        at android.os.Handler.handleCallback(Handler.java:938) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loopOnce(Looper.java:233) 
        at android.os.Looper.loop(Looper.java:334) 
        at android.app.ActivityThread.main(ActivityThread.java:8396) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:582) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1068)

问题原因及解决方案

核心问题

你用@ViewModelInject标记了SongViewModel的构造函数，但在Fragment中获取ViewModel时使用了默认的by viewModels()，这个方式不会调用Hilt的ViewModel工厂，而是尝试通过无参构造函数创建实例，导致崩溃。

修复步骤

更新ViewModel注解：
废弃的@ViewModelInject已被替换为@HiltViewModel，修改SongViewModel代码：

import dagger.hilt.android.lifecycle.HiltViewModel
import javax.inject.Inject

@HiltViewModel
class SongViewModel @Inject constructor(
    musicServiceConnection: MusicServiceConnection
) : ViewModel() {
    // 原有代码不变
}

修改Fragment中获取ViewModel的方式：
将Fragment中的：

private val songViewModel: SongViewModel by viewModels()

替换为Hilt专属的扩展方法：

import androidx.hilt.navigation.fragment.hiltViewModel

private val songViewModel: SongViewModel by hiltViewModel()

确认依赖配置：
确保Module级别的build.gradle中包含Hilt ViewModel相关依赖（版本需与Hilt核心依赖匹配）：

implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0"
kapt "androidx.hilt:hilt-compiler:1.0.0"

清理并重建项目：
执行Build -> Clean Project，再执行Build -> Rebuild Project，确保注解处理器生成正确的代码。

内容的提问来源于stack exchange，提问作者Sidharth

Android点击标题崩溃：无法创建SongViewModel实例求助

SongFragment代码 #

SongViewModel代码 #

Logcat错误信息 #

问题原因及解决方案 #

核心问题 #