如何在Activity中实例化ViewModelFactory

Question

有人可以帮我如何在 Activity 中实例化 VIEWModel FACTORY

有人可以帮我如何在 Activity 中实例化 VIEWModel FACTORY

主要活动

        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)


        val viewModelFactory = DiaryViewModelFactory(diaryDao)
       val viewModel = ViewModelProvider(this).get(DiaryViewModel::class.java)

查看模型工厂

    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        if (modelClass.isAssignableFrom(DiaryViewModel::class.java)) {
            @Suppress("UNCHECKED_CAST")
            return DiaryViewModel(diaryDao) as T
        }
        throw IllegalArgumentException("Unknown ViewModel class")
    }
}

应用类

    val database : DiaryDatabase by lazy {
        DiaryDatabase.getDatabase(this)
    }
}

道类

interface DiaryDao {
    @Query("SELECT * from diary WHERE id = :id")
    fun getItem(id: Int): Flow<Entry>

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    suspend fun insert(entry: Entry)

    @Update
    suspend fun update(entry: Entry)

    @Delete
    suspend fun delete(entry: Entry)

    @Query("SELECT * from diary ORDER BY id ASC")
    fun getItems(): Flow<List<Entry>>
}

Answer 1

最后像这样实例化viewModelFactory

 val viewModel: DiaryViewModel by viewModels{
        DiaryViewModel.DiaryViewModelFactory((application as DiaryApplication).database.diaryDao())
    }