Question

我有一个按字母顺序排序的名称列表，现在我想在表格视图中显示这些名称。我正在努力为每个字母分组这些名字。

我的代码如下所示：

let sections:Array<AnyObject> = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
var usernames = [String]()

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{

    let cellID = "cell"

    let cell: UITableViewCell = self.tv.dequeueReusableCellWithIdentifier(cellID) as UITableViewCell

    cell.textLabel?.text = usernames[indexPath.row]

return cell
}

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

    return usernames.count
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int{

    return 26
}


func sectionIndexTitlesForTableView(tableView: UITableView) -> [AnyObject]!{

    return self.sections
}

func tableView(tableView: UITableView,
    sectionForSectionIndexTitle title: String,
    atIndex index: Int) -> Int{

        return index
}

func tableView(tableView: UITableView,
    titleForHeaderInSection section: Int) -> String?{

        return self.sections[section] as? String
}

这一切都很有效，除了让我的表格视图结束的分组：

enter image description here

所以我知道你应该可以在数组中使用过滤函数，但我不明白如何实现它。

有关如何继续的任何建议将不胜感激。

Answer 1

在Swift 4中，Dictionary(grouping:by:)被引入以通过任意谓词将序列归类为字典。

此示例将分组字典映射到自定义结构Section

struct Section {
    let letter : String
    let names : [String]
}

...

let usernames = ["John", "Nancy", "James", "Jenna", "Sue", "Eric", "Sam"]

var sections = [Section]()

override func viewDidLoad() {
    super.viewDidLoad()

    // group the array to ["N": ["Nancy"], "S": ["Sue", "Sam"], "J": ["John", "James", "Jenna"], "E": ["Eric"]]
    let groupedDictionary = Dictionary(grouping: usernames, by: {String($0.prefix(1))})
    // get the keys and sort them
    let keys = groupedDictionary.keys.sorted()
    // map the sorted keys to a struct
    sections = keys.map{ Section(letter: $0, names: groupedDictionary[$0]!.sorted()) }
    self.tableView.reloadData()
}


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

    let cellID = "cell"
    let cell = tableView.dequeueReusableCell(withIdentifier: cellID, for: indexPath)
    let section = sections[indexPath.section]
    let username = section.names[indexPath.row]
    cell.textLabel?.text = username
    return cell
}

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

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

func sectionIndexTitles(for tableView: UITableView) -> [String]? {
    return sections.map{$0.letter}
}

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

Answer 2

下载CountryList Json文件并放入项目

https://gist.github.com/keeguon/2310008

   var json = NSArray()
   var arr_name = NSArray()
   var arrIndexSection : NSArray = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]


override func viewDidLoad() {

   let path = Bundle.main.path(forResource: "countries", ofType: "json")
    let data = NSData(contentsOfFile: path! )
    json = (try! JSONSerialization.jsonObject(with: data as! Data, options: JSONSerialization.ReadingOptions.mutableContainers)) as! NSArray
    arr_name = json.value(forKey: "name") as! NSArray;

    tableview.reloadData()
    super.viewDidLoad()
}
// Side List in tableview
public func numberOfSections(in tableView: UITableView) -> Int {
    return 26
}
public func sectionIndexTitles(for tableView: UITableView) -> [String]? {
    return self.arrIndexSection as? [String] //Side Section title
}
public func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int
{
    return index
}


public func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return arrIndexSection.object(at: section) as? String
}


// number of rows in table view
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
    let predicate = NSPredicate(format: "SELF beginswith[c] %@", arrIndexSection.object(at: section) as! CVarArg)
    let arrContacts = (arr_name as NSArray).filtered(using: predicate)
    return arrContacts.count;

}

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
    let cell : TableViewCell=self.tableview.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! TableViewCell
    let predicate = NSPredicate(format: "SELF beginswith[c] %@", arrIndexSection.object(at: indexPath.section) as! CVarArg)
    let arrContacts = (arr_name as NSArray).filtered(using: predicate) as NSArray
    cell.textLabel?.text = arrContacts.object(at: indexPath.row) as? String
    return cell
}

Answer 3

您可以使用字母键将带有名称的数组放入字典中。

例如

var names = ["a": ["and", "array"], "b": ["bit", "boring"]]; // dictionary with arrays setted for letter keys

然后你需要以下一种方式访问字典中的值

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
    return names[usernames[section]].count; // maybe here is needed to convert result of names[...] to NSArray before you can access count property
}

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{

    let cellID = "cell"

    let cell: UITableViewCell = self.tv.dequeueReusableCellWithIdentifier(cellID) as UITableViewCell

    cell.textLabel?.text = names[usernames[indexPath.section]][indexPath.row]; // here you access elements in arrray which is stored in names dictionary for usernames[indexPath.section] key

return cell
}

Answer 4

如果您的数据数组未预定义，这是实现相同目标的一种方法。

假设我们的类是ViewController。

class ViewController: UIViewController {

     var contactDictionary = [String: [TTContact]]() //TTContact is a model, it has firstName and lastName properties
     var keys = [String]()
     var alphabets = (97...122).map { "\(Character(UnicodeScalar.init($0)))" }.map { $0.uppercased() } //Populating alphabets
     ... // other properties


    override func viewDidLoad() {
        super.viewDidLoad()
        //set delegate and register cell for your tableView
        self.setContacts()
    }

    private func self.setContacts() {
         //Loop through your array, take the firstName, and the first character of that string.
         //Check the uppercase value of that character, if it's an alphabet or not, otherwise, we'd place "#" for the names starting with a number in the header.

         var temp = [String: [TTContact]]() //A temporary array
         for contact in self.contacts {
             if let firstName = contact.firstName, !firstName.isEmpty { //In my case, the firstName is an optional string
                let firstChar = "\(firstName.first!)".uppercased()
                if alphabets.contains(firstChar) {
                    var array = temp[firstChar] ?? []
                    array.append(contact)
                    temp[firstChar] = array
                } else {
                    var array = temp["#"] ?? []
                    array.append(contact)
                    temp["#"] = array
                }
            }
        }
        self.keys = Array(temp.keys).sorted() //Populating and sorting all the keys alphabetically.
        for key in self.keys { self.contactDictionary[key] = temp[key] }
        //reload table
    }
}

extension: ViewController: UITableViewDelegate, UITableViewDataSource {

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

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.contactDictionary[keys[section]]?.count ?? 0
    }

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

        let key = self.keys[indexPath.section]
        let cell: //dequeue your cell here.
        if let row = self.contactDictionary[key]?[indexPath.row] {
            cell.display(with: row) //Bind your cell's outlets with the properties
            return cell
        }

        return UITableViewCell()
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let key = self.keys[indexPath.section]
        if let row = self.contactDictionary[key]?[indexPath.row] {
            //handle selection.
        }
    }

    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? { //You can use viewForHeaderInSection either.
        return self.keys[section]
    }

}

Answer 5

var nameList = ["Abc","Bbc","Cbc",......]//whatever it is
var arrNameList = [[nameList]]()
var str = String()

override func viewDidLoad() {

  str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

  for i : Int in 0 ..< (str.count) {
      var arr = [nameList]()
        for j : Int in 0 ..< nameList.count {
          let name = nameList[j]
          let index = str.index(str.startIndex, offsetBy: i)
          let char = str[index]
          if name.first == char {
              arr.append(name)
          }
      }
      arrNameList.append(arr)
   }
}

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

func tableView(_ tableView: UITableView, titleForHeaderInSection 
section: Int) -> String? {
  let index = str.index(str.startIndex, offsetBy: section)
  let char = str[index]
  return char
}

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

func tableView(_ tableView: UITableView, heightForHeaderInSection 
section: Int) -> CGFloat {
  return 40
}

func tableView(_ tableView: UITableView, heightForRowAt indexPath: 
IndexPath) -> CGFloat {
  return 40
}

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

  let cell = tableView.dequeueReusableCell(withIdentifier: "cell", 
  for: indexPath) as! NameListTableViewCell

  let name = arrNameList[indexPath.section][indexPath.row]
  cell.nameLbl.text = name

  cell.selectionStyle = .none
  return cell
}

Answer 6

var frndsName = ["Vanitha","Ilakkiya","Parveen","Divya","Seetha","Madhavi","Ashwini","Sangeetha","Swathi","Don","Priyanka","Tamilselvi","Premlatha","Prashanthi","Rekha","Ajitha","Praveena","Indhusree","Nisha","Priya","Lavanya","Sandhiya","Gejalakshmi","Pavithra","Abinaya"]
    let sections = ["*","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","#"]
    var dividedArray:NSMutableArray = []

    override func viewDidLoad() {
        super.viewDidLoad()
        for i in sections{
            let dummyArray:NSMutableArray = []
            for j in frndsName{
                if  i.first!  == j.first! {
                  dummyArray.add(j)
                }
            }
           dividedArray.add(dummyArray)
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
    func numberOfSections(in tableView: UITableView) -> Int {
     return 26
    }

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

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
        let dummyArray = dividedArray[indexPath.section] as! NSMutableArray
        cell?.textLabel?.text = dummyArray[indexPath.row] as? String

        return cell!
          }
    func sectionIndexTitles(for tableView: UITableView) -> [String]? {
        return self.sections
    }
    func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int {
        return index
    }
    internal func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return self.sections[section] as String
    }
}

在桌子视图的按字母顺序的部分在迅速

6 个答案: