无法与表视图标题中的控件交互

我决定在我的应用程序中使用一个表头视图来保存一个搜索栏和一个UISegmentedControl。这是 viewDidLoad 视图控制器的:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 65, 320, 44)];
    [self.searchBar sizeToFit];
    [self.searchBar setUserInteractionEnabled:YES];
    [self setSearchController:[[UISearchDisplayController alloc] initWithSearchBar:self.searchBar contentsController:self]];

    self.mainSegment = [[UISegmentedControl alloc] initWithItems:@[@"YouTube", @"iTunes"]];
    [self.mainSegment setFrame:CGRectMake(8, 109, 305, 29)];
    [self.mainSegment setSelectedIndex:0];
    [self.mainSegment addTarget:self action:@selector(searchTypeChanged:) forControlEvents:UIControlEventValueChanged];
    [self.mainSegment setUserInteractionEnabled:YES];

    UIView* headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 65)];
    [headerView setBackgroundColor:[UIColor clearColor]];
    [headerView addSubview:self.searchBar];
    [headerView addSubview:self.mainSegment];
    [headerView bringSubviewToFront:self.searchBar];
    [headerView bringSubviewToFront:self.mainSegment];
    [headerView setUserInteractionEnabled:YES];

    self.tableView.tableHeaderView = headerView;
    self.tableView.userInteractionEnabled = YES;
}

这会产生良好的结果:

但是,我无法与搜索栏或分段控件交互。如上所示,我尝试将userInteractionEnabled设置为YES,但问题仍然存在。有什么想法吗?