<Page x:Class="BKDashboardTemp.ComboBoxCustom"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"              
             xmlns:b="http://schemas.microsoft.com/xaml/behaviors"
             xmlns:local="clr-namespace:Assets.BKCycling.Scripts.ViewController.ViewModel.Generic.ComboBox"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800" x:Name="vComboBoxCustom">
    
        <ComboBox x:Name="cmbControl" ItemsSource="{Binding ItemsSource, ElementName=vComboBoxCustom}"
                    DisplayMemberPath="{Binding DisplayMember, ElementName=vComboBoxCustom}"
                    SelectedValuePath ="{Binding ValueMember, ElementName=vComboBoxCustom}"
                    Loaded="cmbControl_Loaded">
            <b:Interaction.Triggers>
                <b:EventTrigger EventName="SelectionChanged">
                    <b:InvokeCommandAction Command="{Binding SelectedItemChangedCommand, ElementName=vComboBoxCustom}"/>
                </b:EventTrigger>
            </b:Interaction.Triggers>
        </ComboBox>
</Page>

#define NOESIS
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using Noesis;

namespace BKDashboardTemp
{
    /// <summary>
    /// Lógica de interacción para ComboBoxCustom.xaml
    /// </summary>
    public partial class ComboBoxCustom : Page
    {
        //public NoesisEventCommand SelectedItemChangedCommand { get; set; } = new NoesisEventCommand();
        private ComboBox _cmbControl;
        public NoesisEventCommand LoadedCommand { get; set; } = new NoesisEventCommand();

        public object ItemsSource
        {
            get { return (object)GetValue(ItemsSourceProperty); }
            set { SetValue(ItemsSourceProperty, value); }
        }

        public static readonly DependencyProperty ItemsSourceProperty =
            DependencyProperty.Register(nameof(ItemsSource), typeof(object), typeof(ComboBoxCustom), new PropertyMetadata(null));

        public string DisplayMember
        {
            get { return (string)GetValue(DisplayMemberProperty); }
            set { SetValue(DisplayMemberProperty, value); }
        }

        public static readonly DependencyProperty DisplayMemberProperty =
            DependencyProperty.Register(nameof(DisplayMember), typeof(string), typeof(ComboBoxCustom), new PropertyMetadata(default(string)));

        public string ValueMember
        {
            get { return (string)GetValue(ValueMemberProperty); }
            set { SetValue(ValueMemberProperty, value); }
        }

        public static readonly DependencyProperty ValueMemberProperty =
            DependencyProperty.Register(nameof(ValueMember), typeof(string), typeof(ComboBoxCustom), new PropertyMetadata(default(string)));

        public NoesisEventCommand SelectedItemChangedCommand
        {
            get { return (NoesisEventCommand)GetValue(SelectedItemChangedCommandProperty); }
            set { SetValue(SelectedItemChangedCommandProperty, value); }
        }

        public static readonly DependencyProperty SelectedItemChangedCommandProperty =
            DependencyProperty.Register(nameof(SelectedItemChangedCommand), typeof(NoesisEventCommand), typeof(ComboBoxCustom), new PropertyMetadata(default(NoesisEventCommand)));

       
        public ComboBoxCustom()
        {
            InitializeComponent();
        }

#if NOESIS
        private void InitializeComponent()
        {
            NoesisUnity.LoadComponent(this);
            LoadedCommand.AddListener(ButtonClicker);
        }

        private void ButtonClicker(object arg0)
        {

        }


        private void cmbControl_Loaded(object sender, RoutedEventArgs e)
        {
            if (sender is ComboBox cmb && cmb != null)
                _cmbControl = cmb;
        }


        public ItemCollection GetItems()
        {
            ComboBox cmb = this.FindName("cmbControl") as ComboBox;

            return _cmbControl?.Items;
        }

        // public static T FindChild<T>(DependencyObject parent, string childName)
        //where T : DependencyObject
        // {
        //     // Confirm parent and childName are valid. 
        //     if (parent == null)
        //     {
        //         return null;
        //     }

        //     T foundChild = null;

        //     int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
        //     for (int i = 0; i < childrenCount; i++)
        //     {
        //         DependencyObject child = VisualTreeHelper.GetChild(parent, i);
        //         // If the child is not of the request child type child
        //         var childType = child as T;
        //         if (childType == null)
        //         {
        //             // recursively drill down the tree
        //             foundChild = FindChild<T>(child, childName);

        //             // If the child is found, break so we do not overwrite the found child. 
        //             if (foundChild != null)
        //             {
        //                 break;
        //             }
        //         }
        //         else if (!string.IsNullOrEmpty(childName))
        //         {
        //             var frameworkElement = child as FrameworkElement;
        //             // If the child's name is set for search
        //             if (frameworkElement != null && frameworkElement.Name == childName)
        //             {
        //                 // if the child's name is of the request name
        //                 foundChild = (T)child;
        //                 break;
        //             }

        //             // Need this in case the element we want is nested
        //             // in another element of the same type
        //             foundChild = FindChild<T>(child, childName);
        //         }
        //         else
        //         {
        //             // child element found.
        //             foundChild = (T)child;
        //             break;
        //         }
        //     }

        //     return foundChild;
        // }
#endif
    }
}

public partial class ComboBoxCustom : Page
{
    protected override bool ConnectEvent(object source, string eventName, string handlerName)
    {
        if (eventName == "Loaded" && handlerName == "cmbControl_Loaded")
        {
            ((ComboBox)source).Loaded += this.cmbControl_Loaded;
            return true;
        }
        return false;
    }
    ...
}

private void InitializeComponent()
{
    NoesisUnity.LoadComponent(this);
    _cmbControl = (ComboBox)FindName("cmbControl");
    LoadedCommand.AddListener(ButtonClicker);
}