如何使用视图模型将数据从DialogFragment发送到Fragment

Question

我试图使用ViewModel将数据从DialogFragment发送到Fragment，但Fragment和Dialog Fragment似乎都引用了ViewModel的不同实例。所以我无法访问数据。有什么办法可以解决这个问题吗？感谢

这是我的碎片

@AndroidEntryPoint
class FragmentToReceiveData:BaseFragment(R.layout.fragment_1){
private val viewModel: AddScheduleViewModel by viewModels()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
Log.d(TAG, "onViewCreated: $viewModel")   // will print ...MyViewModel@62274cc  
viewModel.dataFromDialog.observe(viewLifecycleOwner){
//nothing happens
} 
}
.
.
.
private fun openDialog(){
val action=FragmentToReceiveDataDirections.actionFragmentToReceiveDataToExampleDialog()
findNavController().navigate(action)
//exampleDialog.show(requireActivity().supportFragmentManager, "alarmDialog") //same issue      
}

}

这是ViewModel:

class MyViewModel @ViewModelInject constructor(){
var dataFromDialog=MutableLiveData<SomeClass>()

fun saveDataFromDialog(data:SomeClass){
dataFromDialog.value=data      
}
}

这是我的DialogFragment

@AndroidEntryPoint
class ExampleDialog:DialogFragment() {
val viewModel:MyViewModel by viewModels()
override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
Log.d(TAG, "onCreateDialog: $viewModel")   // will print ...MyViewModel@125436
.
.
.
viewMode.saveDataFromDialog(data)
}
}

第页。S： 我使用的是单活动体系结构，所以我不确定activityViewModels((是否是一个好主意

Answer 1

为了在片段之间共享ViewModel，可以使用activityViewModels()。例如

class SharedViewModel : ViewModel() {
...
}
class MasterFragment : Fragment() {
// Use the 'by activityViewModels()' Kotlin property delegate
// from the fragment-ktx artifact
private val model: SharedViewModel by activityViewModels()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
...
}
}
class DetailFragment : Fragment() {
// Use the 'by activityViewModels()' Kotlin property delegate
// from the fragment-ktx artifact
private val model: SharedViewModel by activityViewModels()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
...
}
}

请在这里阅读android文档中的更多内容：https://developer.android.com/topic/libraries/architecture/viewmodel#sharing