RoutedEvents: Drag And Drop

<Window x:Class="RoutedEvents.DragAndDrop"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="DragAndDrop" Height="350" Width="550">
  <StackPanel>
    <TextBox Padding="12" VerticalAlignment="Center" HorizontalAlignment="Center">Drag from this TextBox</TextBox>
    <Label Padding="12" Background="LightGoldenrodYellow" VerticalAlignment="Center"  HorizontalAlignment="Center"
           MouseDown="lblSource_MouseDown">Or this Label</Label>
    <Label Background="LightGoldenrodYellow"
           VerticalAlignment="Center" HorizontalAlignment="Center" Padding="20"
      AllowDrop="True" Drop="lblTarget_Drop">To this Label</Label>
  </StackPanel>
</Window>

//File:Window.xaml.cs


using System;
using System.Collections.Generic;
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.Shapes;

namespace RoutedEvents
{
    public partial class DragAndDrop : System.Windows.Window
    {
        public DragAndDrop()
        {
            InitializeComponent();
        }

        private void lblSource_MouseDown(object sender, MouseButtonEventArgs e)
        {
            Label lbl = (Label)sender;
            DragDrop.DoDragDrop(lbl, lbl.Content, DragDropEffects.Copy);
        }

        private void lblTarget_Drop(object sender, DragEventArgs e)
        {
            ((Label)sender).Content = e.Data.GetData(DataFormats.Text);
        }

        private void lblTarget_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.Text))
                e.Effects = DragDropEffects.Copy;
            else
                e.Effects = DragDropEffects.None;
        }
    }
}