Working with if statements and booleans in wpf c# - wpf

Question

In a WPF form .NET framework, I'm trying to achieve the following (seemingly) simple task:
I have 3 buttons and 3 textboxes:
Button 1
Textbox1
Button 2
Textbox2
Button 3
Textbox3
If I click button 1, I want textbox 1 to read true and the other 2 false. If I click button 2, I want textbox 2 to show true and the others false and the same for button 3 and textbox 3 respectively.
I thought I could achieve this by setting the value of all of the Booleans to either true or false depending on the button that has been clicked using the click event, but don't get the expected result
using System;
using System.Windows;
using System.Threading;
using System.Windows.Threading;
namespace WPF_Test
{
public partial class MainWindow : Window
{
bool value1;
bool value2;
bool value3;
public MainWindow()
{
InitializeComponent();
if (value1 == true)
{
textbox1.Text = value1.ToString();
} else if (value2 == true){
textbox2.Text = value2.ToString();
} else if (value3 == true){
textbox3.Text = value3.ToString();
}
}
private void button1_Click(object sender, RoutedEventArgs e)
{
value1 = true;
value2 = false;
value3 = false;
}
private void button2_Click(object sender, RoutedEventArgs e)
{
value1 = false;
value2 = true;
value3 = false;
}
private void button3_Click(object sender, RoutedEventArgs e)
{
value1 = false;
value2 = false;
value3 = true;
}
}
}
Any idea what I might be missing?

Answer 1

referencing Rekshino's comment:
Just move the code in the constructor after InitializeComponent to the separate method and then call it at the bottom each Button.Click event handler. – Rekshino
however, my limited knowledge does not certify that this is the 'best' version so for this I refer to D M's answer as well

Answer 2

In order to update the UI in WPF by binding to a value in the code behind, you need to change the fields to properties and implement the INotifyPropertyChanged interface. There's a really good answer on how to do this by Marc Gravell.
public partial class MainWindow : Window, INotifyPropertyChanged
{
private bool _value1;
public bool value1
{
get => _value1;
set => SetField(ref _value1, value);
}
private void button1_Click(object sender, RoutedEventArgs e)
{
value1 = true;
}
// Implementation of INotifyPropertyChanged with a
// SetField helper method to ensure you're only
// notifying when a value actually changes.
public event PropertyChangedEventHandler? PropertyChanged;
protected void OnPropertyChanged(string? propertyName)
=> PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
protected bool SetField<T>(ref T field, T value, [CallerMemberName] string? propertyName = null)
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
}