SfComboBox SelectionChanged connection to MVVM

[Matthew Bailey]

I'm trying to use a ComboBox to initiate a Command to open a SfPopupView, but I can't quite seem to get the Command linking set up.

I thought doing something like this:

<combobox:SfComboBox
      DisplayMemberPath="Category"
      VerticalOptions="FillAndExpand"
      Grid.Column="0"
      Grid.Row="1"
      x:Name="SelectByDropDown"
      MultiSelectMode="None"
      TextSize="Small"
      DropDownTextSize="Small"
      DropDownCornerRadius="2"
      SelectedItem="{Binding SelectBySelection}"
      DropDownTextColor="{StaticResource DarkGrey}"
      SelectionChanged="{Binding SelectByChanged_Behavior}"
      DataSource="{Binding SelectionCriteria}"/>

And in my code behind I have:

public ICommand SelectBySelection_Behavior
{
      get
      {
              return new Command(() => CallForSelectionCriteria());
      }
}

public void CallForSelectionCriteria()
{
     
}

I can't figure out how to open the SfPopupView whenever SelectedItem changes. Can someone help?

[Muneesh Kumar G]

Hi Matthew Bailey, 

 

Greetings from Syncfusion.  

 

We have analyzed your requirement “How to open the SfPopupView whenever SelectedItem changes” from our side. We have prepared the simple sample for your requirement. Please try the attached below sample and let us know if you have any concern on this. 

 

Code Snippet: 

<StackLayout> 

        <combobox:SfComboBox IsEditableMode="True" DataSource="{Binding EmployeeCollection}" DisplayMemberPath="Name"> 

            <combobox:SfComboBox.Behaviors> 

                <local:SelectionChangedBehavior/> 

            </combobox:SfComboBox.Behaviors> 

        </combobox:SfComboBox> 

    </StackLayout> 

public class SelectionChangedBehavior : Behavior<SfComboBox> 

    { 

        public ICommand SelectBySelection_Behavior 

        { 

            get 

            { 

                return new Command(() => CallForSelectionCriteria()); 

            } 

        } 

        public void CallForSelectionCriteria() 

        { 

            // This method called while select the item from suggestion box in SfComboBox. You can open the SfPopupView whenever SelectedItem changes. 

        } 

        protected override void OnAttachedTo(SfComboBox bindable) 

        { 

            bindable.SelectionChanged += Bindable_SelectionChanged; 

            base.OnAttachedTo(bindable); 

        } 

        private void Bindable_SelectionChanged(object sender, SelectionChangedEventArgs e) 

        { 

            SelectBySelection_Behavior.CanExecute(true); 

            SelectBySelection_Behavior.Execute(true); 

        } 

        protected override void OnDetachingFrom(SfComboBox bindable) 

        { 

            bindable.SelectionChanged -= Bindable_SelectionChanged; 

            base.OnDetachingFrom(bindable); 

        } 

    } 

 

Sample Link: 

https://www.syncfusion.com/downloads/support/directtrac/general/ze/GettingStarted1109204753 

 

Please check the above sample and let us know if you require any further assistance on this. 

 

Thanks, 

Muneesh Kumar G.