// 调用时刻:当一个cell选中的时候就会调用,并且一个cell取消选中的时候也会调用
 - (void)setSelected:(BOOL)selected animated:(BOOL)animated 

[self.categoryTableView reloadData]; 
// 默认选中第0个cell
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.categoryTableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionNone]; 

- (void)viewDidLoad {
 [super viewDidLoad];
 
 self.title = @"推荐关注";
 self.automaticallyAdjustsScrollViewInsets = NO;
 _categoryTableView.contentInset = UIEdgeInsetsMake(64, 0, 0, 0);
 _userTableView.contentInset = UIEdgeInsetsMake(64, 0, 0, 0);
 // 分类tableView注册cell
 [_categoryTableView registerNib:[UINib nibWithNibName:@"XMGCategoryCell" bundle:nil] forCellReuseIdentifier:categoryID];
 // 用户tableView注册cell
 [_userTableView registerNib:[UINib nibWithNibName:@"XMGSubTagCell" bundle:nil] forCellReuseIdentifier:userID];
 // 请求分类数据
 [self loadCategoryData];
 // 添加上下拉刷新
 [self setupRefreshView]; 
}
- (void)setupRefreshView
{
 // 下拉刷新
 // 当松手,并且下拉刷新完全显示的时候,就会触发下拉刷新
 MJRefreshNormalHeader *header = [MJRefreshNormalHeader headerWithRefreshingTarget:self refreshingAction:@selector(loadNewUserData)];
 header.automaticallyChangeAlpha = YES;
 self.userTableView.mj_header = header;
 
 // 上拉刷新
 MJRefreshAutoNormalFooter *footer = [MJRefreshAutoNormalFooter footerWithRefreshingTarget:self refreshingAction:@selector(loadMoreUserData)];
 footer.automaticallyHidden = YES;
 self.userTableView.mj_footer = footer;
}
 
- (void)loadCategoryData
{
 AFHTTPSessionManager *mgr = [AFHTTPSessionManager xmg_manager];
 
 NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
 parameters[@"a"] = @"category";
 parameters[@"c"] = @"subscribe";
 
 [mgr GET:XMGBaseUrl parameters:parameters progress:nil success:^(NSURLSessionDataTask * _Nonnull task, NSDictionary * _Nullable responseObject) {
 NSArray *dictArr = responseObject[@"list"];
 
 _categorys = [XMGCategoryItem mj_objectArrayWithKeyValuesArray:dictArr];
 
 [self.categoryTableView reloadData];
 
 // 默认选中第0个cell
 NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
 [self.categoryTableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionNone];
 
 [self tableView:self.categoryTableView didSelectRowAtIndexPath:indexPath];
 
 } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) { 
 }];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
 if (tableView == _categoryTableView) { // 显示分类TableView
 return _categorys.count;
 }
 return _selectCategoryItem.users.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
 if (tableView == _categoryTableView) { // 显示分类TableView
 XMGCategoryCell *cell = [tableView dequeueReusableCellWithIdentifier:categoryID];
 cell.item = _categorys[indexPath.row];
 return cell;
 } 
 XMGSubTagCell *cell = [tableView dequeueReusableCellWithIdentifier:userID];
 cell.user = _selectCategoryItem.users[indexPath.row];
 return cell;
}
 
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
 if (tableView == _categoryTableView) {
 return 44;
 }
 return 60 + 1;
}
// 点击cell就会调用
// 必须用户手动点击cell才会触发
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
 if (tableView == _categoryTableView) {
 // 记录选中分类模型
 _selectCategoryItem = _categorys[indexPath.row];
 // 点击分类cell
 // 判断之前有没有数据
 if (_selectCategoryItem.users.count) {
  [self.userTableView reloadData];
  self.userTableView.mj_footer.hidden = _selectCategoryItem.page > _selectCategoryItem.total_page; 
  return;
 }
 // 请求右边用户数据
 [self loadNewUserData]; 
 } 
}

// 没有更多数据的时候,隐藏上拉刷新控件
// 判断当前分类用户组 有没有更多用户组
// 加载更多用户数据
- (void)loadMoreUserData
{
 [self.mgr.tasks makeObjectsPerformSelector:@selector(cancel)];
 
 NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
 parameters[@"a"] = @"list";
 parameters[@"c"] = @"subscribe";
 parameters[@"category_id"] = _selectCategoryItem.id;
 parameters[@"page"] = @(_selectCategoryItem.page);
 
 [self.mgr GET:XMGBaseUrl parameters:parameters progress:nil success:^(NSURLSessionDataTask * _Nonnull task, NSDictionary * _Nullable responseObject) {
 
 [self.userTableView.mj_footer endRefreshing];
 
 _selectCategoryItem.page++;
 NSArray *dictArr = responseObject[@"list"];
 
 NSArray *users = [XMGUserItem mj_objectArrayWithKeyValuesArray:dictArr];
 
 // 取出数组中所有元素,添加到新数组
// [_selectCategoryItem.users addObject:users];
 [_selectCategoryItem.users addObjectsFromArray:users];
 
 [self.userTableView reloadData];
 
 // 控制上拉控件是否显示,一定要在reloadData之后
 self.userTableView.mj_footer.hidden = _selectCategoryItem.page > _selectCategoryItem.total_page;
 } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) { 
 }];
}

// 加载更新用户数据
- (void)loadNewUserData
{
 _selectCategoryItem.page = 1;
 [self.mgr.tasks makeObjectsPerformSelector:@selector(cancel)];
 
 NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
 parameters[@"a"] = @"list";
 parameters[@"c"] = @"subscribe";
 parameters[@"category_id"] = _selectCategoryItem.id;
 
 [self.mgr GET:XMGBaseUrl parameters:parameters progress:nil success:^(NSURLSessionDataTask * _Nonnull task, NSDictionary * _Nullable responseObject) {
 
 _selectCategoryItem.page++;
 
 // 记录当前分类总页码数
 _selectCategoryItem.total_page = [responseObject[@"total_page"] integerValue];
 
 // 结束刷新
 [self.userTableView.mj_header endRefreshing];
 
 NSArray *dictArr = responseObject[@"list"];
 
 _selectCategoryItem.users = [XMGUserItem mj_objectArrayWithKeyValuesArray:dictArr];
 
 [self.userTableView reloadData];
 
 self.userTableView.mj_footer.hidden = _selectCategoryItem.page > _selectCategoryItem.total_page;
 
 } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) { 
 }];
}