如何在同一个视图控制器中使用多个搜索控制器？

import UIKit

class ViewController: UIViewController, UISearchResultsUpdating, UISearchBarDelegate {
    var searchController1: UISearchController!
    var searchController2: UISearchController!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建第一个搜索控制器
        searchController1 = UISearchController(searchResultsController: nil)
        searchController1.searchResultsUpdater = self
        searchController1.searchBar.delegate = self
        searchController1.searchBar.placeholder = "Search 1"
        
        // 创建第二个搜索控制器
        searchController2 = UISearchController(searchResultsController: nil)
        searchController2.searchResultsUpdater = self
        searchController2.searchBar.delegate = self
        searchController2.searchBar.placeholder = "Search 2"
        
        // 将搜索栏添加到导航栏
        navigationItem.titleView = searchController1.searchBar
        
        // 将第二个搜索栏添加到视图中
        let searchBar2 = searchController2.searchBar
        searchBar2.frame.origin.y = searchBar2.frame.height
        view.addSubview(searchBar2)
    }
    
    // 实现 UISearchResultsUpdating 协议方法，处理搜索结果更新
    func updateSearchResults(for searchController: UISearchController) {
        // 根据搜索栏的文本进行搜索，并更新搜索结果的展示
    }
    
    // 实现 UISearchBarDelegate 协议方法，处理搜索栏的交互
    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        // 处理搜索按钮点击事件
    }
}