public class MovingObject
{
protected Control control;
public MovingObject(Control ctrl)
{
control = ctrl;
}
public Control MovingControl
{
get { return control; }
}
}

public class User32
{
[DllImport("User32.dll")]
public static extern int GetWindowRect(IntPtr handle, ref Rectangle rect);
}

public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
AllowDrop = true;
listBox1.MouseDown += new MouseEventHandler(listBox1_MouseDown);
DragEnter += new DragEventHandler(Form2_DragEnter);
DragDrop += new DragEventHandler(Form2_DragDrop);
}
void Form2_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(MovingObject)))
{
MovingObject movingObj = e.Data.GetData(typeof(MovingObject)) as MovingObject;
if (movingObj != null)
{
Rectangle rect = Rectangle.Empty;
User32.GetWindowRect(Handle, ref rect);
movingObj.MovingControl.Location = new Point(e.X - rect.Location.X - 6, e.Y - rect.Location.Y - 34);
Controls.Add(movingObj.MovingControl);
}
}
}
void Form2_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(MovingObject)))
e.Effect = DragDropEffects.Copy;
}
void listBox1_MouseDown(object sender, MouseEventArgs e)
{
DoDragDrop(new MovingObject(listBox1), DragDropEffects.Copy);
}
}