MainWindow.xaml.cs

		MapEditMode _mapEditMode = MapEditMode.normal;

		private void wpfMap1_MapClick(object sender, ThinkGeo.MapSuite.WpfDesktopEdition.MapClickWpfMapEventArgs e) {

					if (_mapEditMode == MapEditMode.add_text) {
				_mapEditMode = MapEditMode.adding_text;
				wpfMap1.Cursor = Cursors.Arrow;

				var canvas = new Canvas();
				TextEditor editor = null;
				editor = new TextEditor(str => {
					//TODO: save string to map

					canvas.Children.Remove(editor);
					mapGrid.Children.Remove(canvas);

					_mapEditMode = MapEditMode.normal;
				});

				// Set margin to the location of the mouse click.
				editor.Margin = new Thickness(e.ScreenX, e.ScreenY, 0, 0);
				canvas.Children.Add(editor);
				mapGrid.Children.Add(canvas);

				return;
			}
}

		private void MenuItemAddText_Click(object sender, RoutedEventArgs e) {
			// Set special cursor mode.
			if (_mapEditMode != MapEditMode.add_text) {
				_mapEditMode = MapEditMode.add_text;
				wpfMap1.Cursor = Cursors.IBeam;
			} else {
				_mapEditMode = MapEditMode.normal;
				wpfMap1.Cursor = Cursors.Arrow;
			}

		}

		private enum MapEditMode {
			normal,
			add_text,
			adding_text
		}

TextEditor.xaml

<UserControl x:Class="LabelingExample.UserControls.TextEditor"
             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"
			 Width="300"
			 Height="30">

	<TextBox Name="txtEditor" BorderThickness="1">
		<TextBox.Background>
			<SolidColorBrush Color="White" Opacity="0.2" />			
		</TextBox.Background>
		
	</TextBox>
</UserControl>

TextEditor.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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 LabelingExample.UserControls {
	/// <summary>
	/// Interaction logic for TextEditor.xaml
	/// </summary>
	public partial class TextEditor : UserControl {
		public TextEditor(Action<string> saveCallback) {
			InitializeComponent();

			this.Loaded += (sender, e) => {

				Action saveText = () => {
					if (null != saveCallback) {
						saveCallback(txtEditor.Text);
					}
				};

				txtEditor.Focus();


				txtEditor.LostFocus += (sndr, ev) => saveText();
				txtEditor.KeyUp += (sndr, ev) => {
					if (ev.Key == Key.Enter) {
						if (Keyboard.Modifiers == ModifierKeys.Control) {
							txtEditor.Text += Environment.NewLine;
							txtEditor.Select(txtEditor.Text.Length, 0);
						} else {
							saveText();
						}
					}
				};

			};
		}

	}
}