c# winform drag & drop

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
 
namespace DragAndDrop
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            this.AllowDrop = true;
            this.MouseDown += new MouseEventHandler(dropSource_MouseDown);
            this.DragEnter += new DragEventHandler(dropTarget_DragEnter);
            this.DragDrop += new DragEventHandler(dropTarget_DragDrop);
 
        }     
        private void Form1_Load(object sender, EventArgs e)
        {
 
        }   
        private void dropSource_MouseDown(object sender, MouseEventArgs e)
        {
            DoDragDrop(dropSource.Text, DragDropEffects.Copy);
        }
 
        private void dropTarget_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(string)))
            {
                e.Effect = DragDropEffects.Copy;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }
        private void dropTarget_DragDrop(object sender, DragEventArgs e)
        {
            dropTarget.Text = (string)e.Data.GetData(DataFormats.StringFormat);
        }
        
    }
}