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表格视图中返回包含搜索名称的帖子，但不知道如何执行此操作。

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而不是String类型的元素。 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)
        }
    }
}

或者干脆使用受@Jay 评论启发的filter之类的高阶方法。

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