DataGridView Drag-Drop (Sürükle-Bırak)

Datagridview’de satırların yerlerini sürükle-bırak ile değiştirmek isterseniz, aşağıdaki 4 eventtaki (MouseMove, MouseDown, DragDrop, DragOver) değişiklikleri yapmanız yeterli olacaktır:

private Rectangle dragBoxFromMouseDown;
private int rowIndexFromMouseDown;
private int rowIndexOfItemUnderMouseToDrop;

private void datagridview1_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. 
            if (datagridview1.Rows.Count != 0)
            {
                DragDropEffects dropEffect = datagridview1.DoDragDrop(
                  datagridview1.Rows[rowIndexFromMouseDown], DragDropEffects.Move);
            }
        }
    }
}


private void datagridview1_MouseDown(object sender, MouseEventArgs e)
{
    // Get the index of the item the mouse is below.
    rowIndexFromMouseDown = datagridview1.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;

}

private void datagridview1_DragDrop(object sender, DragEventArgs e)
{
    // The mouse locations are relative to the screen, so they must be 
    // converted to client coordinates.
    Point clientPoint = datagridview1.PointToClient(new Point(e.X, e.Y));

    // Get the row index of the item the mouse is below. 
    rowIndexOfItemUnderMouseToDrop =
      datagridview1.HitTest(clientPoint.X, clientPoint.Y).RowIndex;
 
    // If the drag operation was a move then remove and insert the row.

    //This line is necessary for avoid missing out row when you drag                                     

if (rowIndexOfItemUnderMouseToDrop != -1)
    {
       if (e.Effect == DragDropEffects.Move)
       {
          DataGridViewRow rowToMove = e.Data.GetData(
                  typeof(DataGridViewRow)) as DataGridViewRow;
                datagridview1.Rows.RemoveAt(rowIndexFromMouseDown);
                datagridview1.Rows.Insert(rowIndexOfItemUnderMouseToDrop, rowToMove);
                this.DragDrop(this, e);
            }
        }
    }
}

private void datagridview1_DragOver(object sender, DragEventArgs e)
{
    e.Effect = DragDropEffects.Move;
}