WPF

<ListBox Grid.Row="3" Grid.ColumnSpan="3" Margin="3" SelectionMode="Multiple"
                            ItemsSource="{Binding Children}" SelectedItem="{Binding SelectedChild}"          SelectionChanged="Children_SelectionChanged">

<Style TargetType="{x:Type local:ControlBasedOnUserControl}">
    <Setter Property="Width" Value="50" />
    <Setter Property="Height" Value="50" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:ControlBasedOnUserControl}">
                <Border>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style TargetType="{x:Type local:ControlBasedOnUserControl}">
    <Setter Property="Width" Value="50" />
    <Setter Property="Height" Value="50" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:ControlBasedOnUserControl}">
                <Border Width="{TemplateBinding Width}" Height="{TemplateBinding Height}">
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<telerik:RadComboBox ItemsSource="{Binding CurrencyList}"
  DisplayMemberPath="Currency"
  SelectedValuePath="CurrencyID"
  SelectedValue="{Binding SelectedIssuance.IssuanceCurrencyID, Mode=TwoWay}"
  IsSynchronizedWithCurrentItem="True"
  SelectedItem="{Binding SelectedCurrency,Mode=OneWayToSource}" />

var openPicker = new FileOpenPicker();
          openPicker.FileTypeFilter.Add("*");

          var files = await openPicker.PickMultipleFilesAsync();

public static class closeWindow
{
    public static object WinObject;

    public static void CloseParent()
    {
        using ((System.IDisposable)closeWindow.WinObject)
        {
            ((Window)WinObject).Close();
        }
    }
}

public partial class SavedDrafts : Window
{
    public SavedDrafts()
    {
        InitializeComponent();

        LoadMe();

    }

    public void loadMe()
    {
        closeWindow.WinObject = this;
    }

}

// From me the child view, open a new window and close my parent Window.//


                Intake1 window = new Intake1();
                window.Show();

                closeWindow.CloseParent();

public delegate void OnMessageReceivedEventHandler(object sender, object message);

   public static class Message
   {
       static List<OnMessageReceivedEventHandler> listeners = new List<OnMessageReceivedEventHandler>();

       public static void AddListener(OnMessageReceivedEventHandler onMsgReceived)
       {
           listeners.Add(onMsgReceived);
       }

       public static void RemoveListener(OnMessageReceivedEventHandler onMsgReceived)
       {
           listeners.Remove(onMsgReceived);
       }

       public static void SendMessage(object sender, object msg)
       {
           foreach (OnMessageReceivedEventHandler m in listeners)
               if (m != null)
                   m(sender, msg);
       }
   }

C#


public partial class MainWindow : Window
    {
        ObservableCollection<string> _items = new ObservableCollection<string> { "a1", "a2" };
 

        public ObservableCollection<string> Items
 
        {
 
            get { return _items; }
 
            set { _items = value; }
 
        }
        public MainWindow()
        {
            InitializeComponent();
            var aa = a1;
        }
    }


XAML

<StackPanel>
       <ComboBox Name="a1" ItemsSource="{Binding Items}">
 

       </ComboBox>
   </StackPanel>