navBar 上添加searchBar

    //导航条的搜索条
        UISearchBar *searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(500.0f,0.0f,250.0f,44.0f)];
        searchBar.delegate = self;
        [searchBar setPlaceholder:@"搜索"];
        
        //将搜索条放在一个UIView上
        UIView *searchView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 768, 44)];
        searchView.backgroundColor = [UIColor clearColor];
        [searchView addSubview:searchBar];
        
        self.navigationItem.titleView = searchView;
        [searchBar release];
        [searchBiew release];

或者

UISearchBar* searchBar=[[[UISearchBar alloc]initWithFrame:CGRectMake(560, 0, 150,40)]autorelease];
   
//searchBar.delegate = self;
[searchBar setPlaceholder:@"search"];
[self.navigationController.navigationBar addSubview:searchBar];