/// <summary>
/// The MouseDown event of the source control is used to initiate a drag operation.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">A MouseEventArgs that contains the event data.</param>
private void numericUpDown1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Sets a reference to the control that initiated the DragDrop operation, so
// that the target control can implement logic to handle data dragged from
// specific controls differently.
sourceControl = numericUpDown1;
// Record the mouse button that initiated this operation in order to allow
// target controls to respond differently to drags with the right or left
// mouse buttons.
mouseButton = e.Button;
// This initiates a DragDrop operation, specifying that the data to be dragged
// with be the value stored in the numericUpDown1 control. This also specifies
// that ONLY the Copy effect will be allowed.
numericUpDown1.DoDragDrop(numericUpDown1.Value.ToString(), DragDropEffects.Copy);
}
