如何使用 SearchBar 在 tableview 中搜索 firebase 数据？

Question

我已经设置了一个 tableview，它从 firebase 实时数据库中检索数据，并将这些数据存储在一个数组（'posts'）中，格式如下：

（姓名：nil，contactEmail：可选（“35345345235”），contactPhoneNum：可选（“contact@gmail.com”），年龄：可选（“25”），性别：nil，lastSeen：nil， profileDescription: nil)

我想实现一个搜索栏来过滤帖子的名称值并在tableview中返回包含搜索名称的帖子，但不知道该怎么做。

这是我的代码：

import UIKit
import Firebase
import FirebaseDatabase
import SwiftKeychainWrapper
import FirebaseAuth

class FeedVC: UITableViewController, UISearchBarDelegate{
    
    @IBOutlet weak var searchBar: UISearchBar!
    
    var currentUserImageUrl: String!
    var posts = [postStruct]()
    var selectedPost: Post!
    var filteredPosts = [postStruct]()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        getUsersData()
        getPosts()
        searchBar.delegate = self
        // Do any additional setup after loading the view.
   //     tableView.register(PostCell.self, forCellReuseIdentifier: "PostCell")
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    
    func getUsersData(){

        guard let userID = Auth.auth().currentUser?.uid else { return }
        Database.database().reference().child("users").child(userID).observeSingleEvent(of: .value) { (snapshot) in
            if let postDict = snapshot.value as? [String : AnyObject] {
                self.tableView.reloadData()
            }
        }
    }
    
    struct postStruct {
        let name : String!
        let contactEmail : String!
        let contactPhoneNum : String!
        let age : String!
        let gender : String!
        let lastSeen : String!
        let profileDescription : String!
    }
    
    func getPosts() {
        let databaseRef = Database.database().reference()
        databaseRef.child("firstName").queryOrderedByKey().observe( .childAdded, with: {
                    snapshot in
                    let name = (snapshot.value as? NSDictionary)!["name"] as? String
                    let contactEmail = (snapshot.value as? NSDictionary
                    )!["contactEmail"] as? String
                    let contactPhoneNum = (snapshot.value as? NSDictionary
                    )!["contactPhoneNum"] as? String
                    let age = (snapshot.value as? NSDictionary
                    )!["age"] as? String
                    let gender = (snapshot.value as? NSDictionary
                    )!["gender"] as? String
                    let lastSeen = (snapshot.value as? NSDictionary
                    )!["lastSeen"] as? String
                    let profileDescription = (snapshot.value as? NSDictionary
                    )!["profileDescription"] as? String
            self.posts.append(postStruct(name: name,contactEmail:contactEmail, contactPhoneNum:contactPhoneNum, age:age, gender:gender, lastSeen:lastSeen, profileDescription:profileDescription))
            DispatchQueue.main.async {
                        self.tableView.reloadData()
                    }
                })
    }
    
    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        print("posts count = ", filteredPosts.count)
        return filteredPosts.count

   }
    
    override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
      //  tableView.dequeueReusableCell(withIdentifier: "PostCell")!.frame.size.height
        return 230
    }
   override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        guard let cell = tableView.dequeueReusableCell(withIdentifier: "PostCell") as? PostCell else { return UITableViewCell() }
    cell.nameLabel?.text = filteredPosts[indexPath.row].name
        cell.contactEmailLabel?.text = filteredPosts[indexPath.row].contactEmail
        cell.contactPhoneNumLabel?.text = filteredPosts[indexPath.row].contactPhoneNum
        cell.ageLabel?.text = filteredPosts[indexPath.row].age
        cell.genderLabel?.text = filteredPosts[indexPath.row].gender
        cell.lastSeenLabel?.text = filteredPosts[indexPath.row].lastSeen
        cell.profileDescriptionLabel?.text = filteredPosts[indexPath.row].profileDescription
        print(filteredPosts)
        return cell
    }
    
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
          filteredPosts = posts.filter { $0.name?.lowercased().contains(searchText.lowercased()) == true }
}


}

Answer 1

遍历posts 将提供Post 类型的元素，而不是String。这是修复：

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    filteredPosts = []
    for post in posts {
        if post.name?.lowercased().contains(searchText.lowercased()) == true {
            filteredPosts.append(post)
        }
    }
}

或者干脆使用filter 之类的高阶方法，灵感来自@Jay 的评论。

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    filteredPosts = posts.filter { $0.name?.lowercased().contains(searchText.lowercased()) == true }
}