无法通过 onDateSet 方法为视图模型中的 livedata 赋值

Question

i cant update the value of dateTxt and timeTxt, it is always null. i tried calling setDate from a fragment and it works. And the value date Mutablelive data remains null. When i call function from onDateset it actually come inside viewModel and the value never updates.

My viewModel

 class OrderViewModel @ViewModelInject constructor(
    private val networkHelper: NetworkHelper,
    private val firebaseRepository: FirebaseRepository

) : ViewModel(){

  val date:MutableLiveData<Date> = MutableLiveData()
    val dateTxt:MutableLiveData<String> = MutableLiveData()
    val timeTxt:MutableLiveData<String> = MutableLiveData("Set Time")

fun setDate(year:Int?, month:Int?, day:Int?,hour:Int?, minute:Int?){

        viewModelScope.launch {
            if (networkHelper.isNetworkConnected()){
                date.value = Date(year,month,day,hour,minute)

                if(year!=null && month!=null && day!=null){
                    val c = Calendar.getInstance()
                    c.set(Calendar.YEAR,year)
                    c.set(Calendar.MONTH,month)
                    c.set(Calendar.DAY_OF_MONTH,day)
                    val dateString= DateFormat.getDateInstance(DateFormat.FULL).format(c.time).toString()
                    dateTxt.value = dateString
                }

                if (hour!=null && minute!=null){
                    val c = Calendar.getInstance()
                    c.set(Calendar.HOUR,hour)
                    c.set(Calendar.MINUTE,minute)
                    timeTxt.value = DateFormat.getDateInstance(DateFormat.SHORT).format(c.time).toString()

                }
            }
        }
    }
}

DatePickerDailog

@AndroidEntryPoint
class DatePickerDialog :DialogFragment(), DatePickerDialog.OnDateSetListener{

    private val viewmodel:OrderViewModel by viewModels()

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val c = Calendar.getInstance()
        val year = c.get(Calendar.YEAR)
        val month = c.get(Calendar.MONTH)
        val day = c.get(Calendar.DAY_OF_MONTH)
        return DatePickerDialog(requireContext(),this,year,month,day)
    }

    override fun onDateSet(view: DatePicker?, year: Int, month: Int, dayOfMonth: Int) {

        viewmodel.setDate(year,month,dayOfMonth,null,null)

    }


}

Answer 1

Solved

I actually created two instances of viewmodel, to fix that i used shared viewModel, like

private val viewmodel:OrderViewModel by activityViewModels()