iOS开发实现搜索框(UISearchController)

- (void)viewDidLoad {
    [super viewDidLoad];

    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    self.searchController.searchResultsUpdater = self;
    self.searchController.dimsBackgroundDuringPresentation = false;
    [self.searchController.searchBar sizeToFit];
    self.tableView.tableHeaderView = self.searchController.searchBar;

}

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController {
    [self.searchList removeAllObjects];
    //在iOS开发中，系统提供了NSPredicate这个类给我们进行一些匹配、筛选操作
    NSPredicate *searchPredicate = [NSPredicate predicateWithFormat:@"SELF CONTAINS[c] %@", self.searchController.searchBar.text];
    self.searchList = [[self.dataList filteredArrayUsingPredicate:searchPredicate] mutableCopy];
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tableView reloadData];
    });
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    if (!self.searchController.active) {
        return self.dataList.count;
    }
    else{
        return self.searchList.count;
    }
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *ID = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];
    }
    if (!self.searchController.active) {
        cell.textLabel.text = self.dataList[indexPath.row];
    }
    else{
        cell.textLabel.text = self.searchList[indexPath.row];
    }
    return cell;

}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    if (self.searchController.active) {
        self.searchController.active = NO;
        [self.searchController.searchBar removeFromSuperview];
    }
}