Question

我是编码的新手，并且一直在按字母顺序按部分对我的tableview行中的数据（名称）进行排序。我设法创建了部分和索引，但无法弄清楚如何对名称进行排序;每个部分都有相同的A-Z名称列表。

我有一个具有对象的Names模型类：nameTitle，nameDetail，image，纬度坐标和经度坐标。 tableView显示nameTitle.text。其他对象在另一个视图控制器中显示或访问。

以下是我的TableViewController的示例代码：

import UIKit

class TableOfContentsVC: UIViewController, UITableViewDelegate,  UITableViewDataSource {

@IBAction func backButtonPressed(_ sender: Any) {

    dismiss(animated: false, completion: nil)

}

@IBOutlet weak var tableView: UITableView?

var name = [Name]()

override func viewDidLoad() {
    super.viewDidLoad()

    let cell001 = Name (nameTitle: "Acker" , nameDetail: "Details for Acker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell001)

    let cell002 = Name (nameTitle: "Baker" , nameDetail: "Details for Baker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell002)

    let cell003 = Name (nameTitle: "Caker" , nameDetail: "Details for Caker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell003)

    let cell004 = Name (nameTitle: "Dacker" , nameDetail: "Details for Dacker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell004)

    let cell005 = Name (nameTitle: "Ecker" , nameDetail: "Details for Ecker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell005)

    let cell006 = Name (nameTitle: "Facker" , nameDetail: "Details for Facker are listed here.", picture: UIImage (named: "somePicture.jpg"), latCoordinates: 38, longCoordinates: 119)

    name.append (cell006)
}
func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int {
    let currentCollation = UILocalizedIndexedCollation.current() as UILocalizedIndexedCollation
    return currentCollation.section(forSectionIndexTitle: index)
}

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    let currentCollation = UILocalizedIndexedCollation.current() as UILocalizedIndexedCollation
    let sectionTitles = currentCollation.sectionTitles as NSArray
    return sectionTitles.object(at: section) as? String

}

func sectionIndexTitles(for tableView: UITableView) -> [String]? {
    let currentCollation = UILocalizedIndexedCollation.current() as UILocalizedIndexedCollation
    return (currentCollation.sectionIndexTitles as NSArray) as? [String]


}

func numberOfSections(in tableView: UITableView) -> Int {
    let currentCollation = UILocalizedIndexedCollation.current() as UILocalizedIndexedCollation
    let sectionTitles = currentCollation.sectionTitles as NSArray
    return sectionTitles.count

}


func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    if let cell = tableView.dequeueReusableCell(withIdentifier: "NameCell", for: indexPath) as? NameCell {

        let name = Name [indexPath.row]

        cell.updateUI(name: name)

    return cell


    } else {

        return UITableViewCell()

    }
}


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

            return name.count


}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    let name = names [indexPath.row]
    performSegue(withIdentifier: "ContentVC", sender: name)

}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

    if let destination = segue.destination as? ContentVC {

        if let name = sender as? Name {
            destination.name = name
        }
    }
}  
}

除了让名字按字母顺序显示在相应部分之外，一切都很有效。我尝试了10种不同的方法来实现这一点，没有任何帮助。任何建议将不胜感激。提前谢谢！

Answer 1

你这样做是错误的。您没有使用数据来生成索引。

我们假设您拥有一系列数据var name: [Name]

定义每个Name所属的部分：

extension Name {
    var titleFirstLetter: String {
        return String(self.nameTitle[self.nameTitle.startIndex]).uppercased()
    }
}

从您的数据生成索引

// all the first letters in your data
let firstLetters = names.map { $0.titleFirstLetter }
// some letters appear multiple times, let's remove duplicates
let uniqueFirstLetters = Array(Set(firstLetters))
// sort them
// this is your index
let sortedFirstLetters = uniqueFirstLetters.sorted()

生成部分

let sections: [[Name]] = sortedFirstLetters.map { firstLetter in
    return names
        .filter { $0.titleFirstLetter == firstLetter } // only names with the same first letter in title
        .sorted { $0.nameTitle < $1.nameTitle } // sort them
}

使用它们

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return sortedFirstLetters[section]
}

func sectionIndexTitles(for tableView: UITableView) -> [String]? {
    return sortedFirstLetters
}

func numberOfSections(in tableView: UITableView) -> Int {
    return sections.count // or sortedFirstLetters.count
}

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

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let name = sections[indexPath.section][indexPath.row]
    ...
}

编辑 - 完整示例：

class Name {
    let nameTitle: String
    let nameDetail: String

    init(nameTitle: String, nameDetail: String) {
        self.nameTitle = nameTitle
        self.nameDetail = nameDetail
    }

    var titleFirstLetter: String {
        return String(self.nameTitle[self.nameTitle.startIndex]).uppercased()
    }
}

class ViewController : UIViewController, UITableViewDelegate, UITableViewDataSource {
    @IBOutlet weak var tableView: UITableView?

    var names: [Name] = []

    var sortedFirstLetters: [String] = []
    var sections: [[Name]] = [[]]

    override func viewDidLoad() {
        super.viewDidLoad()

        let cell001 = Name(nameTitle: "Acker", nameDetail: "Details for Acker are listed here.")
        names.append (cell001)

        let cell002 = Name(nameTitle: "Baker", nameDetail: "Details for Baker are listed here.")
        names.append (cell002)

        let cell003 = Name(nameTitle: "Caker" , nameDetail: "Details for Caker are listed here.")
        names.append (cell003)

        let cell004 = Name(nameTitle: "Dacker", nameDetail: "Details for Dacker are listed here.")
        names.append (cell004)

        let cell005 = Name(nameTitle: "Ecker", nameDetail: "Details for Ecker are listed here.")
        names.append (cell005)

        let cell006 = Name(nameTitle: "Facker", nameDetail: "Details for Facker are listed here.")
        names.append (cell006)

        let firstLetters = names.map { $0.titleFirstLetter }
        let uniqueFirstLetters = Array(Set(firstLetters))

        sortedFirstLetters = uniqueFirstLetters.sorted()
        sections = sortedFirstLetters.map { firstLetter in
            return names
                .filter { $0.titleFirstLetter == firstLetter }
                .sorted { $0.nameTitle < $1.nameTitle }
        }
    }

    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return sortedFirstLetters[section]
    }

    func sectionIndexTitles(for tableView: UITableView) -> [String]? {
        return sortedFirstLetters
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return sections.count
    }

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

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let name = sections[indexPath.section][indexPath.row]

        let cell = UITableViewCell(style: .subtitle, reuseIdentifier: nil)
        cell.textLabel?.text = name.nameTitle
        cell.detailTextLabel?.text = name.nameDetail

        return cell
    }
}

如何使用自定义模型类按部分按字母顺序对tableView中的数据进行排序？

1 个答案: