mchsamples-wpf-.net/ex_NoFocusableTreeView/MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace ex_NoFocusableTreeView
{
    /// <summary>
    /// Logique d'interaction pour MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            int lastPos = test.CaretIndex;
            test.Text = string.Format("{0}{1}{2}", test.Text.Substring(0, test.CaretIndex), "TEST", test.Text.Substring(test.CaretIndex));
            test.CaretIndex = lastPos + "TEST".Length;
        }
    }
}