UISearchController使用

iOS8之前我们使用UISearchDisplayController做TableView的本地搜索

iOS8提供实现搜索功能的SDK：UISearchController（iOS8.0之后）、UISearchDisplayController（iOS8.0之前，iOS8.0之后不建议再使用）。

遵守UISearchResultsUpdating协议

 @interface ZWRecommendationFocusViewController()<UISearchResultsUpdating>
 @property (strong, nonatomic) NSArray *list;
 @property (strong, nonatomic) NSMutableArray *searchList;
 @property (strong, nonatomic)UISearchController *searchController;
 @end

 -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
 {
     return (!self.searchController.active)?:;
 }

 -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
 {
     return (!self.searchController.active)?self.list.count:self.searchList.count;
 }

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
 {
     ZWFocusList *list=(!self.searchController.active)?self.list[indexPath.row]:self.searchList[indexPath.row];
     static NSString *identifier = @"cell";
     ZWFocusListTableViewCell *cell = [ZWFocusListTableViewCell cellWithTableView:tableView identifier:identifier];
     cell.list = list;
     return cell;
 }

 /**
  *  UISearchController作为UITableView的tableHeaderView
  */
 -(void)addSearchBar
 {
     //创建UISearchController对象
     UISearchController *searchController = [[UISearchController alloc]initWithSearchResultsController:nil];
     //是否添加半透明覆盖层。为YES，搜索时，背景会变暗（背景变模糊）。默认为YES
     searchController.dimsBackgroundDuringPresentation = NO;
     //是否隐藏导航栏。为YES，搜索时，UINavigationBar会隐藏。默认为YES
     searchController.hidesNavigationBarDuringPresentation = YES;
     //NO表示UISearchController在present时，可以覆盖当前controller。默认为NO
     searchController.definesPresentationContext = NO;
     //搜索栏表头视图
     self.tableView.tableHeaderView = searchController.searchBar;

     [searchController.searchBar sizeToFit];
     searchController.searchResultsUpdater = self;

     searchController.searchBar.placeholder=@"请输入名称或者数字";
     searchController.searchBar.autocapitalizationType=UITextAutocapitalizationTypeNone;
     //    searchController.searchBar.showsCancelButton=YES;//显示取消按钮
     //自适应
     [searchController.searchBar sizeToFit];
     //    searchController.searchBar.frame = CGRectMake(0, 0, 0, 44);
     //    searchController.searchBar.prompt=@"请输入关键字";
     self.searchController = searchController;
 }

 - (void)updateSearchResultsForSearchController:(UISearchController *)searchController{
     NSString *searchString = self.searchController.searchBar.text;
     //NSPredicate 谓词
     NSPredicate *preicate = [NSPredicate predicateWithFormat:@"theme_name LIKE[c] %@", searchString];
     if (self.searchList!= nil) {
         [self.searchList removeAllObjects];
     }
     //过滤数据
     self.searchList= [NSMutableArray arrayWithArray:[self.list filteredArrayUsingPredicate:preicate]];
     //刷新表格
     [self.tableView reloadData];
 }