private void DgvCategories_MouseMove(object sender, MouseEventArgs e)
{
if ((e.Button & MouseButtons.Left) == MouseButtons.Left)
{
// 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.
DragDropEffects dropEffect = DgvCategories.DoDragDrop(
DgvCategories.Rows[rowIndexFromMouseDown],
DragDropEffects.Move);
}
}
}
private void DgvCategories_DragDrop(object sender, DragEventArgs e)
{
// The mouse locations are relative to the screen, so they must be
// converted to client coordinates.
Point clientPoint = DgvCategories.PointToClient(new Point(e.X, e.Y));
// Get the row index of the item the mouse is below.
rowIndexOfItemUnderMouseToDrop =
DgvCategories.HitTest(clientPoint.X, clientPoint.Y).RowIndex;
// If the drag operation was a move then remove and insert the row.
if (e.Effect == DragDropEffects.Move)
{
DataGridViewRow rowToMove = e.Data.GetData(
typeof(DataGridViewRow)) as DataGridViewRow;
DgvCategories.Rows.RemoveAt(rowIndexFromMouseDown);
DgvCategories.Rows.Insert(rowIndexOfItemUnderMouseToDrop, rowToMove);
}
}
private void DgvCategories_MouseDown(object sender, MouseEventArgs e)
{
// Get the index of the item the mouse is below.
rowIndexFromMouseDown = DgvCategories.HitTest(e.X, e.Y).RowIndex;
if (rowIndexFromMouseDown != -1)
{
// 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;
}
}