Swift - 在 UITableView 中搜索

Question

这个问题已经有答案了:

Searchbar filtering issue (3 个回答)

已关闭 4 年前。

我试图在我的应用中使用 UISearchBar 搜索我的 Firebase 数据，但我陷入困境。我在 TableView 中成功接收来自 Firebase 的数据。我有一个内存写入应用程序，用户可以创建内存(显示在 firebase 的表格 View 中)。记忆有标题、描述、图片和日期，我希望它能够通过标题搜索记忆。

我这里有一段代码由于某种原因不起作用...如果您能帮助我找出代码中的问题或找到此代码的替代品，我会很高兴:)

MemoryTitles 类:

class MemoryTitles {
    var title : String
    init(withTitle: String) {
        self.title = withTitle
    }
}

内存 View Controller :

class MemoryViewController: UIViewController,UITableViewDelegate,UITableViewDataSource


    // the filtered memories array for the search bar
    var memoriesTitlesArr: [String] = []
    var filteredDataa: [String] = []    

    // connections from storyboard to the code

    @IBOutlet weak var tbl: UITableView!

    @IBOutlet weak var searchBar: UISearchBar!

    // an array of memories
    var memories : [Memory] = []

    var ref = Database.database().reference()
    let sref = Storage.storage().reference()

    var lastIndex : Int = 0
    var strMode : String = ""


    // TableView functions

    // Return the number of rows in section
    // section - an index number identifying a section in tableView.

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if searching {
            return filteredDataa.count
        } else {
            return memories.count
        }

     //   return memories.count
    }

    // Return Cell for row function : an object inheriting from UITableViewCell
    // indexPath - an index path locating a row in tableView.

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "iden")
        if searching {
            cell?.textLabel?.text = filteredDataa[indexPath.row]
        } else {
            var cell : UITableViewCell? = tableView.dequeueReusableCell(withIdentifier: "iden", for: indexPath)

            if cell == nil
            {
                cell = UITableViewCell(style: UITableViewCell.CellStyle.default, reuseIdentifier: "iden")
            }
            let temp = memories[indexPath.row]
            cell?.textLabel?.text = temp.title
            cell?.imageView?.image = temp.image

            return cell!
        }
        return cell!
    }

    // Can edit row : asks the data source to verify that the given row is editable.
    // indexPath - an index path locating a row in tableView.

    func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {

        return true // true if the row indicated by indexPath is editable; otherwise, false.
    }

    // Asks the data source to commit the insertion or deletion of a specified row.
    // indexPath - an index path locating a row in tableView.

    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {

        if editingStyle == .delete // editingStyle - the cell editing style corresponding to a insertion or deletion requested for the row specified by indexPath.
        {
            let temp = self.memories[indexPath.row]
            self.memories.remove(at: indexPath.row)
            self.ref.child("MEmories/\(temp.key)").removeValue()
            tableView.deleteRows(at: [indexPath as IndexPath], with: .fade)
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        ref = Database.database().reference()
        let rightButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(MemoryViewController.barButtonItemClicked(_:)))
        self.navigationItem.setRightBarButton(rightButton, animated: true)
        // Do any additional setup after loading the view.
        self.loadMemories()
        self.tbl.delegate = self
        self.tbl.dataSource = self
    }

    // click on bar-Button function
    @objc func barButtonItemClicked(_ sender:UIBarButtonItem)
    {
        print("+ clicked") // writes "+ clicked"
        let addMemoryViewController = self.storyboard?.instantiateViewController(withIdentifier: "AddMemoryViewController") as! AddMemoryViewController

        self.strMode = "newMemory"
        self.navigationController?.pushViewController(addMemoryViewController, animated: true)
    }
    // Reading from NSUserDefault (A class that provides simple storage of different data types solution.)
    func readFromNSUserDefault()-> Memory?
    {
        let d : UserDefaults = UserDefaults.standard            
            let strTitle = d.object(forKey: "title") as? String
            let strBody = d.object(forKey: "body") as? String
            let strImageRef = d.object(forKey: "imageRef") as? String
            let uid = d.object(forKey: "uid") as? String
            let imageData = d.object(forKey: "imageData") as? Data
            let key = d.object(forKey: "key") as? String
            let date = d.object(forKey: "date") as? NSNumber
            let m = Memory(title: strTitle!, body: strBody!, key: key!, uid: uid!, imageRef: strImageRef!, date: date!) // A variable from type memory
            m.image = UIImage(data: imageData!)
            m.key = key!
            return m
    }

    override func viewDidAppear(_ animated: Bool) {

        let d = UserDefaults.standard
        let newMemory = readFromNSUserDefault()
        let userAdded = d.bool(forKey: "userAdded") //key new user = true
        let userEdited = d.bool(forKey: "userEdited")//key  user edited = true

        if self.strMode == "newMemory" &&  userAdded

        {
            self.memories.append(newMemory!)
            self.tbl.reloadData()
        }

        else if self.strMode == "edit" && userEdited
        {
            memories[lastIndex] = newMemory!
            self.tbl.reloadData()
        }
        d.set(false, forKey: "userAdded")
        d.set(false, forKey: "userEdited")
        d.synchronize()
        self.strMode = " "
    }

    // loading the memories from the Database
    func loadMemories()

    {
       let UID = Auth.auth().currentUser!.uid
       self.ref.child("MEmories").queryOrdered(byChild: "uid").queryEqual(toValue: UID).observeSingleEvent(of: .value, with: {

            snapShot in

            if let dict = snapShot.value as? NSDictionary

            {

                for d in (dict as? Dictionary<String,AnyObject>)!

                {

                    let title = d.value["title"] as?String

                    let body = d.value["body"] as? String

                    let uid = d.value["uid"] as? String

                    let imageRef = d.value["imageRef"] as? String

                    let date = d.value["date"] as? NSNumber


                    let m = Memory(title: title!, body: body!, uid: uid!,imageRef:imageRef!, date: date!)

                    m.key = d.key

                    let tempImageRef = self.sref.child(m.imageRef)


                    tempImageRef.getData(maxSize: 500*1024*1024, completion: {(data,error) in



                        if error == nil

                        {

                            if let imageData = data

                            {

                                m.image = UIImage(data: imageData)

                                self.memories.append(m)

                                self.tbl.reloadData()
                            }
                        }
                    })
                    self.memoriesTitlesArr.append(title!)
                }                
            }//end of if
        })
    }

    // Notifies the view controller that a segue is about to be performed.
    // segue - The segue object containing information about the view controllers involved in the segue.
    // senderThe object that initiated the segue.
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let identifier = segue.identifier
        {
            if identifier == "goToEdit"
            {
                let indexPath = self.tbl.indexPathForSelectedRow
                let addMemoryViewController = segue.destination as! AddMemoryViewController
                self.strMode = "edit"
                self.lastIndex = (indexPath?.row)!
                addMemoryViewController.mode = self.strMode
                addMemoryViewController.current = memories[(indexPath?.row)!]

            }
        }
    }
    var searching = false
}

extension MemoryViewController: UISearchBarDelegate {
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        filteredDataa = memoriesTitlesArr.filter({ $0.prefix(searchText.count)==searchText.lowercased()})
            searching = true
            tbl.reloadData()

    }
    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        searching = false
        searchBar.text = ""
        tbl.reloadData()
    }
}

Answer 1

以下是如何让它发挥作用。

1.首先，不需要searching维持搜索和不搜索的状态。

2. 其次，使用filteredData作为dataSource对于 tableView而不是memories 。 filteredData最初将包含 memories 中的所有对象，即

var memories : [Memory] = []
lazy var filteredData = self.memories

UITableViewDataSource方法就像，

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.filteredData.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCell(withIdentifier: "iden") {
        cell.textLabel?.text = self.filteredData[indexPath.row].title
        return cell
    }
    return UITableViewCell()
}

现在，在搜索时更新 filteredData经过过滤memories使用相关条件，即

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    self.filteredData = self.memories.filter({ $0.title.hasPrefix(searchText) }) 
    //change the condition as per your requirement......
    self.tbl.reloadData()
}

func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
    searchBar.text = nil
    self.filteredData = self.memories
    self.tbl.reloadData()
}

取消后，重新填写filteredData与整体memories数据。