Room Query 通话同步问题

Question

因此，我创建了一个房间数据库，并且目前被困在从数据库中获取字符串的地方，而我又想用它来显示在警报对话框中。 到目前为止，我尝试了以下两种方法：

binding.btnGetRandomMeal.setOnClickListener {
    mMealViewModel.setTagQuery(binding.etSearchTag.text.toString())

    mMealViewModel.dataToUi.observe(viewLifecycleOwner){result -> result?.apply {
        item = result
        binding.textView.text = item
        askUserForAcceptance(binding.textView.text.toString())   // Variant 1
    }}
    askUserForAcceptance(binding.textView.text.toString())       // Variant 2
}


    private fun askUserForAcceptance(item: String) {
        val builder = AlertDialog.Builder(requireContext())
        builder.setPositiveButton("Yes"){_, _->
            Toast.makeText(requireContext(), "Successfully added.", Toast.LENGTH_SHORT).show()
            findNavController().navigate(R.id.action_getMealFragment_to_dashboardFragment)
        }
        builder.setNegativeButton("No") {_, _ ->}
        builder.setTitle("Random Meal?")
        builder.setMessage("Do you want to accept $item?")
        builder.create().show()
    }
                

这里的问题是，一旦弹出警报对话框，我有时必须多次按否才能再次关闭并且 $item 更改。

在第二个变体中，我在括号外使用了askUserForAcceptance方法，这导致 alertdialog 始终显示上一次按下的 $item，如下所示：

Textview.text = "Textview" -> press button -> Textview.text = "XYZ" -> alertdialog $item = "Textview" -> press button -> Textview.text = "ABC" -> alertdialog $item = "XYZ

** 视图模型**

class MealViewModel(application: Application): AndroidViewModel(application) {

    private val repository: MealRepository

    init {
        val mealDao = MealDatabase.getDatabase(application).mealDao()
        repository = MealRepository(mealDao)
    }

    private val _dataToUi = MutableLiveData<String>()
    val dataToUi: LiveData<String>
        get() = _dataToUi

    suspend fun getSpecificMeal(tag: String): String? {
        return withContext(Dispatchers.IO){
            repository.getSpecificMeal(tag)
        }
    }

    fun setTagQuery(tag: String){
        viewModelScope.launch {
            _dataToUi.value = getSpecificMeal(tag)
        }
    }

存储库

class MealRepository(private val mealDao: MealDao) {

    suspend fun getSpecificMeal(tag: String): String{
        return withContext(Dispatchers.IO){
            mealDao.getSpecificMeal(tag)
        }
    }
}

道

@Dao
interface MealDao {

    @Query("SELECT name FROM meal_data WHERE tag1 LIKE '%' || :tag || '%' OR tag2 LIKE '%' || :tag || '%' 
            OR tag3 LIKE '%' || :tag || '%' ORDER BY RANDOM() LIMIT 1")
    fun getSpecificMeal(tag: String): String

提前谢谢你的帮助。