在项目中突然想把以前的搜索改成UISearchController，随便写个demo用着挺爽，没想到用的项目中会这么多坑，还好很多坑网上都能找到，但是这一个可是给我折腾死了，现在虽然是解决了，还是没找到原因，只能先在这记一下。有哪位发现原因了可要发我一下哟！！！

1. 首先懒加载

#pragma mark - getter
- (UITableView *)tableView {
    if (!_tableView) {
        UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
        tableView.delegate = self;
        tableView.dataSource = self;
        tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
        tableView.backgroundColor = [UIColor clearColor];
        _tableView = tableView;
    }
    return _tableView;
}

- (UISearchController *)searchController {
    if (!_searchController) {
        
        MRCOANewlySearchViewController *searchVC = [[MRCOANewlySearchViewController alloc] init];
        searchVC.newlyViewModel = self.viewModel;
        
        //初始化
        UISearchController *searchController = [[UISearchController alloc] initWithSearchResultsController:searchVC];
//        searchController.delegate = self;
        searchController.searchResultsUpdater = searchVC;
        searchController.dimsBackgroundDuringPresentation = NO;
        
        UISearchBar *searchBar = searchController.searchBar;
        searchBar.placeholder = @"搜索";
        searchBar.searchBarStyle = UISearchBarStyleMinimal;
        [searchBar setBackgroundImage:[UIImage new]];
        [searchBar setBackgroundColor:[UIColor clearColor]];
        
        UIImage *image = [[UIImage imageWithColor:[UIColor whiteColor] size:CGSizeMake(SCREEN_WIDTH, 34)] imageByRoundCornerRadius:5];
        [searchBar setSearchFieldBackgroundImage:image forState:UIControlStateNormal];
        
//        searchBar.searchTextPositionAdjustment = UIOffsetMake(3, 0);
//        CGFloat offsetX = (SCREEN_WIDTH-100) / 2;
//        [searchBar setPositionAdjustment:UIOffsetMake(offsetX, 0) forSearchBarIcon:UISearchBarIconSearch];

        [searchBar setValue:@"取消" forKey:@"_cancelButtonText"];
        
        //UIViewController中的属性，将UISearchViewController的view添加在了当前控制器View上。避免searchBar被遮挡，或者cell跳转时候依然在上面的情况
        self.definesPresentationContext = YES;
        
        _searchController = searchController;
    }
    return _searchController;
}

2. 然后加载到view

#pragma mark - UI
- (void)addSubviews {
    
    self.view.backgroundColor = [UIColor colorWithHexString:@"#ededed"];
    
    UIBarButtonItem *rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"officialAccount_list_icon"] style:UIBarButtonItemStylePlain target:self action:@selector(pushOfficicaAccountList)];
    self.navigationItem.rightBarButtonItem = rightBarButtonItem;
    
    self.tableView.tableHeaderView = self.searchController.searchBar;
    [self.tableView setContentOffset:CGPointMake(0, CGRectGetHeight(self.searchController.searchBar.frame)) animated:NO];
    
    MJRefreshAutoStateFooter *footer = [MJRefreshAutoStateFooter footerWithRefreshingTarget:self refreshingAction:@selector(loadMoreMessage)];
    footer.onlyRefreshPerDrag = YES;
    footer.stateLabel.text = @"正在加载";
    self.tableView.mj_footer = footer;

    [self.view addSubview:self.tableView];
    [self.tableView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.view);
    }];
}

我说一下我这大坑

tableView直接出现了这一片空白，我试图找到规律，在5s手机上测试

屏幕高度568  view高度504 行高定死100
一行        contentSize.height = 616;
两行        contentSize.height = 672;
三行        contentSize.height = 728;
四行        contentSize.height = 784;
...
十行        contentSize.height = 76;


616-100=516
672-200=472
728-300=428
784-400=384

516-472=44
472-428=44
428-384=44

516=44*10+76

到这我也就没再去分析（项目太紧后续也没跟进）

然后我突然想到将searchBar加到一个view上，之后在添加到tableHeaderView，没想到问题竟然解决了

UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, self.searchController.searchBar.height)];
    [headerView addSubview:self.searchController.searchBar];
    self.tableView.tableHeaderView = headerView;

这就是我遇到的奇葩问题，仅记录下有望参考