private void DataGridViewItens_MouseMove(object sender, MouseEventArgs e)
{
if ((e.Button & MouseButtons.Left) != MouseButtons.Left)
{
return;
}
// If the mouse moves outside the rectangle, start the drag.
if (_dragBoxFromMouseDown != Rectangle.Empty && !_dragBoxFromMouseDown.Contains(e.X, e.Y))
{
// Proceed with the drag and drop, passing in the list item.
var dropEffect = DataGridViewItens.DoDragDrop(_itemFromMouseDown, DragDropEffects.Move);
}
}
private void DataGridViewItens_MouseDown(object sender, MouseEventArgs e)
{
// Get the index of the item the mouse is below.
var hittestInfo = DataGridViewItens.HitTest(e.X, e.Y);
if (hittestInfo.RowIndex != -1 && hittestInfo.ColumnIndex != -1)
{
_itemFromMouseDown = _itens[hittestInfo.RowIndex];
// 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.
var 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;
}
}
