XAML Ipmlementation

<Window x:Class="WpfDataBindingDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Data Binding Demo" Height="150" Width="250">
    <Grid Margin="10">
        <StackPanel>
            <TextBox Text="{Binding DisplayText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
            <Button Content="Update Value" Click="UpdateValue_Click" Margin="0,10,0,0"/>
        </StackPanel>
    </Grid>
</Window>

C# Code-Behind and ViewModel

using System.ComponentModel;
using System.Windows;

namespace WpfDataBindingDemo
{
    public partial class MainWindow : Window
    {
        private readonly DataModel model = new DataModel();
        private int updateCount = 0;

        public MainWindow()
        {
            InitializeComponent();
            DataContext = model;
        }

        private void UpdateValue_Click(object sender, RoutedEventArgs e)
        {
            updateCount++;
            model.DisplayText = $"Update #{updateCount}";
        }
    }

    public class DataModel : INotifyPropertyChanged
    {
        private string _displayText = "Initial value";

        public string DisplayText
        {
            get => _displayText;
            set
            {
                _displayText = value;
                OnPropertyChanged(nameof(DisplayText));
            }
        }

        public event PropertyChangedEventHandler? PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}