将数据插入数据库时​​，我没有收到对onChange的更改

Question

我正在尝试使用mvvm架构编写应用程序。但是，当我将数据插入数据库时​​，在onChange上没有收到任何更改。我要实现的逻辑：转到缓存，获取数据。然后，我们转到服务器并接收数据。如果有更改，请同时更新缓存和ui。告诉我我在做什么错了吗？

class PageFragment : BaseFragment() {

    private val pageName= "fly"

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {

        ...

        val viewModel = ViewModelProviders.of(this).get(PageViewModel(activity!!.appliacation)::class.java)

        viewModel.getPages().observe(this, Observer<Page> { page ->
            adapter.contents = page!!.content

        })
        viewModel.pageName = pageName

        return view
    }
}

ViewModel类

class PageViewModel constructor(application: Application) : AndroidViewModel(application) {
    private var repository: Repository = Repository(application)

    private var mutablePages = MutableLiveData<Page>()
    fun getPages(): LiveData<Page> = mutablePages

    var pageName: String = ""
        set(value) {
            field = value
            loadData(value)
        }

    private fun loadData(pageName: String) {
        GlobalScope.launch {
            withContext(Dispatchers.Main) {
                mutablePages.value = repository.getPage(pageName)
            }
        }

    }
}

存储库类

class Repository(context: Context) {

private var dbRepository: DbRepository = DbRepository(context)

....

suspend fun getPage(pageName: String): Page =
            dbRepository.getPage(pageName).let { pagesMapper.dbToBusinessEntity(it) }.also {
//get data from the server and put it into db
//data from the server put into db successful. By this I will not write how I do it. 
                GlobalScope.launch { updatePage(pageName) }
            }

....

    }

DbRepository类

class DbRepository(context: Context) {

private var pagesDao: pagesDao = AppDatabase.getInstance(context).pagesDao()

....

suspend fun getpage(pageName: String): PageDb =
            GlobalScope.async { pagesDao.getPage(pageName) }.await()

....

}

道课

@Dao
interface PagesDao {

    @Query("SELECT * FROM pages WHERE pageName= :pageName")
    fun getPage(pageName: String): PageDb

}

实体数据类

@Entity(tableName = "pages")
data class PageDb(

        var content: List<Any>,
        @PrimaryKey(autoGenerate = false)
        var pageName: String

)

我也想听听对此守则的批评。谢谢！

Answer 1

发现问题出在哪里... 为了通知LiveData数据更改，从数据库中检索数据的方法不应具有suspend关键字。