VB6_DrapDrop.cs

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication8
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            //Do this to allow drap operations
            this.AllowDrop = true;
            this.Label1.AllowDrop = true;
        }

        private void Command1_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void Form_DragOver(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Move;
            var source = e.GetSource();
        }


        private void Label1_DragDrop(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.All;
            var source = e.GetSource();

            Label1.Text = source.Text;
        }

        private void Label1_DragOver(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.All;
            var source = e.GetSource();
        }

        private void Text1_MouseDown(object sender, MouseEventArgs e)
        {
            if (Text1.Text.Length > 0 && e.Button == MouseButtons.Left)
            {
                Text1.BeginDrag(); 
            }
        }

    }
}