iOS13 UISearchController + MJRefresh

最近iOS的客户端适配iOS13，需要将原来的UISearchDisplayController替换为UISearchController，加上页面中存在UITableView + MJRefresh的结构，实际调整中出现了各种细节问题，去查资料，现在iOS这生态...确实没查到什么资料...全靠自己瞎几把调，所以为了方便遇到同样问题的同行，避免浪费无谓的时间，就把适配后的代码放出来，且看代码：
@interface YourViewController ()< UISearchControllerDelegate, UISearchBarDelegate, UISearchResultsUpdating>

/** 搜索vc */
@property (nonatomic, strong) UISearchController *searchController;

/** 联系人列表 */
@property (nonatomic, strong) UITableView *contactTableView;

/** 搜索内容 */
@property (nonatomic, strong) NSString *searchContent;

/** 正常状态数据源 */
@property (nonatomic, strong) NSMutableArray *contactArr;

/** 搜索状态数据源 */
@property (nonatomic, strong) NSMutableArray *searchedContactArr;

@end

@implementation YourViewController

#pragma mark - 生命周期
- (void)viewDidLoad {
    [super viewDidLoad];

    //初始化ui
    [self initView];
}

#pragma mark - tableview DataSource / delegate

 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
 {
    if (self.searchController.isActive && self.searchContent.length > 0) {
        //处于搜索状态且存在搜索内容时
    
    } else {
       //正常状态
   
    }
}


//....省略若干其他无关tableview的代理方法，这些代理方法中区分是否搜索状态的处理逻辑都同上numberOfSectionsInTableView方法


- (void)scrollViewWillBeginDragging:(UIScrollView*)scrollView
{
    //重写这个代理方法，是为了在存在搜索结果时，滑动列表收起键盘
    [self.searchController.searchBar resignFirstResponder];
}



#pragma mark - searchBar delegate
/**
 *  点击cancle按钮时调用
 */
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
    //点击取消按钮后，清空已有搜索结果
    self.searchContent = @"";
    //清空搜索结果列表
    [self.searchedContactArr removeAllObjects];
    //刷新tableview
    [self.contactTableView reloadData];
}



#pragma mark - UISearchController delegate
- (void)updateSearchResultsForSearchController:(UISearchController *)aSearchController {
    //停止刷新状态
    [self.contactTableView.mj_header endRefreshing];

    if (self.searchController.isActive) {
        //搜索状态禁止刷新
        self.contactTableView.mj_header.hidden = YES;
    } else {
        //正常状态允许刷新
        self.contactTableView.mj_header.hidden = NO;
    }

    self.searchContent = aSearchController.searchBar.text;
    //调用搜索方法
    [self getSearchedContactList];
    //得到搜索结果后，刷新UI
    [self.contactTableView reloadData];
}


 #pragma mark - 私有方法

- (void)initView
{
    [self.contactTableView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.left.and.right.equalTo(self.view);
    make.top.equalTo(self.mas_topLayoutGuide);
    make.bottom.equalTo(self.mas_bottomLayoutGuide);
    }];


    //关于UISearchController的所有设置
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    //设置代理
    self.searchController.searchResultsUpdater = self;
    self.searchController.searchBar.delegate = self;
    //进入搜索状态是否隐藏导航栏，yes为隐藏，no为不隐藏；默认是yes
    self.searchController.hidesNavigationBarDuringPresentation = YES;
    //这个属性忘了啥意思，反正有用
    self.searchController.dimsBackgroundDuringPresentation = NO;
    //设置下边这个属性是为了返回到前一个页面，使searchBar消失
    self.definesPresentationContext = YES;
    //设置searchbar相关
    self.searchController.searchBar.placeholder = @"搜索联系人";
    [self.searchController.searchBar setBackgroundColor:[UIColor whiteColor]];
    self.searchController.searchBar.autocapitalizationType = UITextAutocapitalizationTypeNone;
    self.searchController.searchBar.tintColor = SC_COLOR(kColorStressClickable);
    self.searchController.searchBar.delegate = self;
    //隐藏searchBar的分割线
    self.searchController.searchBar.backgroundImage = [[UIImage alloc] init];
    self.searchController.searchBar.frame = CGRectMake(0, 0, SCREEN_WIDTH, 56);
    [self.searchController.searchBar sizeToFit];
    //设置searchBar中的UItextfield
    UITextField *searchBarTextField = [[UITextField alloc] init];
    if (@available(iOS 13.0, *)) {
        searchBarTextField = self.searchController.searchBar.searchTextField;
        searchBarTextField.backgroundColor = [UIColor whiteColor];
    } else {
        searchBarTextField = [self.searchController.searchBar valueForKey:@"_searchField"];
    
        //设置searchbar的背景色和文本框颜色
        for(UIView *view in [[[self.searchController.searchBar subviews] objectAtIndex:0] subviews]){
            if ([view isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) {
                view.alpha = 0.0f;
        } else if([view isKindOfClass:NSClassFromString(@"UISearchBarTextField")] ){
                view.backgroundColor = [UIColor whiteColor];
            }
        }
    }
    [searchBarTextField setFont:[UIFont systemFontOfSize:14]];
    searchBarTextField.layer.cornerRadius = 8.0f;//设置圆角具体根据实际情况来设置
    searchBarTextField.textColor = SC_COLOR(kColorNormalDividerBlockText); //字体颜色
    searchBarTextField.backgroundColor = SC_COLOR(kColorBgLightLightGray); //背景颜色

    //下拉刷新
    self.contactTableView.mj_header = [MJRefreshGifHeader headerWithRefreshingTarget:self refreshingAction:@selector(refresh)];
    self.contactTableView.mj_header.automaticallyChangeAlpha = YES;

    self.contactTableView.separatorStyle = UITableViewCellSeparatorStyleNone;

    //设置列表头部为搜索框
    self.contactTableView.tableHeaderView = self.searchController.searchBar; 
    }


#pragma -mark 懒加载

- (UITableView *)contactTableView
 {
    if (!_contactTableView) {
        _contactTableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
        [self.view addSubview:_contactTableView];
        _contactTableView.dataSource = self;
        _contactTableView.delegate = self;
    
        [_contactTableView registerClass:[YourTableViewCell class] forCellReuseIdentifier:cellIndentify];
    
      //这里我也忘了，不懂自己百度吧
        if (@available(iOS 11.0, *)) {
            _contactTableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        } else {
            self.automaticallyAdjustsScrollViewInsets = NO;
        }
    }
    return _contactTableView;
}

@end
以上关于搜索框的处理的前提是，搜索结果页面和正常展示的页面共用同一套tableview，其他的就不解释了，注释都有...