如何让用户在按下WPF数据网格中的某个键后跳转到下一个适合项？

private void DataGrid_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Tab)
    {
        DataGridCell currentCell = Keyboard.FocusedElement as DataGridCell;
        if (currentCell != null)
        {
            DataGrid dataGrid = FindVisualParent<DataGrid>(currentCell);
            if (dataGrid != null)
            {
                int columnIndex = dataGrid.CurrentCell.Column.DisplayIndex;
                int rowIndex = dataGrid.Items.IndexOf(dataGrid.CurrentItem);

                if (columnIndex < dataGrid.Columns.Count - 1)
                {
                    // 下一个单元格
                    DataGridCell nextCell = dataGrid.Columns[columnIndex + 1].GetCellContent(dataGrid.Items[rowIndex]).Parent as DataGridCell;
                    if (nextCell != null)
                    {
                        nextCell.Focus();
                        e.Handled = true;
                    }
                }
                else if (rowIndex < dataGrid.Items.Count - 1)
                {
                    // 下一行的相同列
                    DataGridCell nextCell = dataGrid.Columns[columnIndex].GetCellContent(dataGrid.Items[rowIndex + 1]).Parent as DataGridCell;
                    if (nextCell != null)
                    {
                        nextCell.Focus();
                        e.Handled = true;
                    }
                }
            }
        }
    }
}

private static T FindVisualParent<T>(DependencyObject child) where T : DependencyObject
{
    DependencyObject parentObject = VisualTreeHelper.GetParent(child);
    if (parentObject == null)
        return null;

    T parent = parentObject as T;
    if (parent != null)
        return parent;
    else
        return FindVisualParent<T>(parentObject);
}