Btukfyl

I am having problems getting the Time property of the TimePicker into my ViewModel.The method on the ViewModel

TimePickerTimeSelected()

is called but BEFORE the Time property is updated.

private DateTimeOffset _datePickerValue;

public DateTimeOffset datePickerValue

 {

     get => _datePickerValue;

     set => SetProperty(ref _datePickerValue, value);

 }

Here isthe XAML

<TimePicker

     Name="timePicker"

     Time="{x:Bind viewModel.timePickerValue,Mode=TwoWay}"

     TimeChanged="{x:Bind viewModel.TimePickerTimeSelected,Mode=TwoWay}">

I want to do some processing with the time when it is selected in the control but the method is called before the timePickerValue is updated.How do I get the new time? ViewModel method:

  public void TimePickerTimeSelected()

  {



  }

In your Xaml you are setting Mode=TwoWay to TimeChanged Event which is invalid, as TmeChange is an Event and not a DependencyProperty.

In order to achieve the desired output please refer to the below code:

Xaml:

<TimePicker

   Name="timePicker"

   Time="{x:Bind ViewModel.TimePickerValue, Mode=TwoWay}"

   TimeChanged="{x:Bind ViewModel.TestTimeChangedEvent}"/>

ViewModel:

  private TimeSpan _timePickerValue;

  public TimeSpan TimePickerValue

  {

     get { return _timePickerValue; }

     set { _timePickerValue = value;}

  }



  public void TestTimeChangedEvent(object sender, TimePickerValueChangedEventArgs e)

  {

     TimePickerValue = e.NewTime;

  }

EDIT

As you don't want to use TimePickerValueChangedEventArgs in your ViewModel, you have to create a custom behavior to get the selected time in your VM.

XAML:

 <TimePicker

     Name="timePicker">

    <Interactivity:Interaction.Behaviors>

       <behaviors:TimeChangedEventBehavior/>

    </Interactivity:Interaction.Behaviors>

 </TimePicker>

Behavior:

  public sealed class TimeChangedEventBehavior : DependencyObject, IBehavior

    {

        public DependencyObject AssociatedObject { get; private set; }



        public void Attach(DependencyObject associatedObject)

        {

            if (!(associatedObject is TimePicker tp))

            {

                throw new ArgumentException("Error Associating Object");

            }



            this.AssociatedObject = associatedObject;



            tp.TimeChanged += OnTimeChanged;

        }



        private void OnTimeChanged(object sender, TimePickerValueChangedEventArgs e)

        {

            var timePicker = (sender as TimePicker);

            var mainVM = (timePicker.DataContext as MainViewModel);

            mainVM.OnTimePickerTimeSelected(timePicker.Time);

        }



        public void Detach()

        {

            if (this.AssociatedObject is TimePicker tp)

            {

                tp.TimeChanged -= this.OnTimeChanged;

            }

        }

    }

ViewModel:

 public void OnTimePickerTimeSelected(TimeSpan selectedTime)

 {

     // Your Logic       

 }