如何在沒有搜索欄的表格視圖中通過 object 設置過濾器？

Question

我有一個表格視圖，我想添加一個按鈕，該按鈕將按給定選項過濾數據。 例如，我只想顯示表中包含“參加”的數據。 這是我的代碼：

 func filterBy(){
    let addEvent = UIAlertController(title: "Sort by:", message: "Sort guests", preferredStyle: .alert)
    let subview = (addEvent.view.subviews.first?.subviews.first?.subviews.first!)! as UIView
    let shapes = UIView()
    shapes.layer.cornerRadius = 30
    shapes.layer.borderWidth = 5
    shapes.layer.borderColor = #colorLiteral(red: 0.9843137255, green: 0.8196078431, blue: 0.8509803922, alpha: 1)
    subview.backgroundColor = #colorLiteral(red: 0.9607843137, green: 0.9333333333, blue: 0.9176470588, alpha: 1)
    subview.tintColor = #colorLiteral(red: 0.9843137255, green: 0.8196078431, blue: 0.8509803922, alpha: 1)
    addEvent.view.tintColor = #colorLiteral(red: 0.4431372549, green: 0.4431372549, blue: 0.4431372549, alpha: 1)
    
    let addSortAction = UIAlertAction(title: "Attending", style: .default) { (action) in
        let sortedBy: () = self.guestsList.sort(by: { $0.attendingStatus ?? "" > $1.attendingStatus ?? ""})
       print(sortedBy)
        self.guestsTableView.reloadData()
    }
    let cancelAction = UIAlertAction(title: "Cancel", style: .default)
    addEvent.addAction(addSortAction)
    addEvent.addAction(cancelAction)
    present(addEvent, animated: true, completion: nil)
}

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

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "guestCell", for: indexPath) as! GuestTableViewCell
    let guest: GuestModel
    guest = guestsList[indexPath.row]
    
    cell.guestNameLabel.text = guest.guestName! + " " + guest.guestFamilyName!
    cell.attendingLabel.text = guest.attendingStatus
    cell.menuLabel.text = guest.menuStatus
    cell.ageLabel.text = guest.ageStatus
    cell.tableLabel.text = guest.tableNo
    
    return cell
}

model：

class GuestModel {
    
    var guestName: String?
    var attendingStatus: String?
    var menuStatus: String?
    var ageStatus: String?
    var tableNo: String?
    var id: String?
    var guestFamilyName: String?
    var guestPhoneNumber: String?
    var guestEmail: String?
}

Answer 1

為了實現你想要的，你可以使用三個全局變量

1. 您在開始時初始化的完整列表 (guestsList)
2. 過濾后的列表，用作表視圖數據源（filteredGuestsList）
3. 搜索到的字符串，它將過濾器應用於列表（在我的情況下，考慮到您將過濾器應用於guestName屬性）

filterBy方法只需要更新搜索到的值，每次要清除或更新搜索到的值時都需要調用該方法。

private var guestsList = [GuestModel]() {
    didSet {
        filteredGuestsList = guestsList
    }
}
private var filteredGuestsList = [GuestModel]() {
    didSet {
        guestsTableView.reloadData()
    }
}
private var search = "" {
    didSet {
        filteredGuestsList = search != "" ? guestsList.filter {
            $0.guestName.uppercased().contains(searchText.uppercased())
        } : guestsList
    }
}

func filterBy(_ text: String) {
    search = text
}

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

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "guestCell", for: indexPath) as! GuestTableViewCell
    let guest = filteredGuestsList[indexPath.row]
    
    cell.guestNameLabel.text = guest.guestName! + " " + guest.guestFamilyName!
    cell.attendingLabel.text = guest.attendingStatus
    cell.menuLabel.text = guest.menuStatus
    cell.ageLabel.text = guest.ageStatus
    cell.tableLabel.text = guest.tableNo
    
    return cell
}