Hi Pankaj, 

I"m not sure what you mean?

Are you saying that when a user hits the up and down key on the grid, you need to move the active row in the collection?

If so, it'd look something like this:

   grid.ItemsSource = this._data;

   grid.AddHandler(UIElement.KeyDownEvent, new KeyEventHandler(grid_KeyDown), true);

        void grid_KeyDown(object sender, KeyEventArgs e)
        {

            if (grid.ActiveCell != null)
            {

                if (e.Key == Key.Down)
                {

                    // B/c the grid already handled the keydown and changed the active cell.

                    int index = grid.ActiveCell.Row.Index - 1;

                    Comic data = (Comic)grid.Rows[index].Data;

                    this._data.Remove(data);

                    this._data.Insert(index + 1, data);

                    // Delay so the row has time to be rendered.

                    this.Dispatcher.BeginInvoke(() =>
                     {

                            grid.ActiveCell = grid.Rows[index + 1].Cells[0];

                        });

                }

                else if(e.Key == Key.Up)

                {

                }

            }            

        } 

Hope this helps, 

-SteveZ