private void Sequence_listBox_DragOver(object sender, DragEventArgs e)
{
// Determine whether string data exists in the drop data. If not, then
// the drop effect reflects that the drop cannot occur.
if (!e.Data.GetDataPresent(typeof(System.String)))
{
e.Effect = DragDropEffects.None;
return;
}
e.Effect = DragDropEffects.Move;
// Get the index of the item the mouse is below.
// The mouse locations are relative to the screen, so they must be
// converted to client coordinates.
indexOfItemUnderMouseToDrop = Sequence_listBox.IndexFromPoint(Sequence_listBox.PointToClient(new Point(e.X, e.Y)));
}
private void Sequence_listBox_MouseDown(object sender, MouseEventArgs e)
{
// Get the index of the item the mouse is below.
indexOfItemUnderMouseToDrag = Sequence_listBox.IndexFromPoint(e.X, e.Y);
if (indexOfItemUnderMouseToDrag != ListBox.NoMatches)
{
// Remember the point where the mouse down occurred. The DragSize indicates
// the size that the mouse can move before a drag event should be started.
Size dragSize = SystemInformation.DragSize;
// Create a rectangle using the DragSize, with the mouse position being
// at the center of the rectangle.
dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2),
e.Y - (dragSize.Height / 2)), dragSize);
}
else
{
// Reset the rectangle if the mouse is not over an item in the ListBox.
dragBoxFromMouseDown = Rectangle.Empty;
}
}