Changing the background color of a cell in a UITableView
The default value for selectedBackgroundView is nil for cells in plain-style tables (UITableViewStylePlain) and non-nil for section-group tables (UITableViewStyleGrouped).
If you’re using a plain-style table, you must alloc an init a new UIView with the desired background color, and then assign it to selectedBackgroundView.
Otherwise, if you just want a gray background, you should use:
cell.selectionStyle = UITableViewCellSelectionStyleGray;
