TableView实现单选，并且默认选中第一行

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    _lastIndex = [NSIndexPath indexPathForRow:0 inSection:0];

    [_tableV selectRowAtIndexPath:_lastIndex animated:YES scrollPosition:UITableViewScrollPositionTop];

    NSIndexPath *path = [NSIndexPath indexPathForItem:0 inSection:0];

    [self tableView:self.tableV didSelectRowAtIndexPath:path];

}

- (void)viewDidLoad {

    [super viewDidLoad];

//    _lastIndex.row = 0;

    // Do any additional setup after loading the view, typica