UITableView仅显示10个单元格/行

Question

我的TableViewController上有两个范围/标签，“All”＆amp; “前10名”。我只希望我的“前10名”标签只显示10个单元格/行而不是显示所有内容。请查看我的图片以获得更好的参考。

P.S：我的UITableView用于使用firebase数据库显示我的活动超过30个展位的实时结果。此外，案例0为“全部”，案例1为“前10名”。

TableViewController

import UIKit
import FirebaseDatabase

var ref: DatabaseReference?
var databaseHandle: DatabaseHandle?
var postData = [String]()
var postData2 = [String]()
var currentpostDataArray = [String]()
var tableDataArray = [tableData]()
var tableDataArray2 = [tableData]()
var searchArray = [tableData]()
var selectedTab = 0

class TableViewController: UITableViewController, UISearchBarDelegate {


    @IBOutlet var searchBar: UISearchBar!

    override func viewDidLoad() {
        super.viewDidLoad()

        setUpSearchBar()

        ref = Database.database().reference()//set the firebase reference

            databaseHandle = ref?.child("Posts2").observe(.value, with: { (snapshot) in
                // Code to execute when a child is added under "Posts"
                postData.removeAll()
                postData2.removeAll()
                tableDataArray.removeAll()


                for child in snapshot.children {
                    let snap = child as! DataSnapshot
                    let key = snap.key
                    let value = String(describing: snap.value!)
                    let rating = (value as NSString).integerValue

                    postData.append(key)
                    postData2.append(value)

                    tableDataArray.append(tableData(boothName: key, boothRating: rating))
                    currentpostDataArray = postData
                }

                self.tableView.reloadData()


            })

        databaseHandle = ref?.child("Posts2").queryOrderedByValue().queryLimited(toLast: 10).observe(.value, with: { (snapshot) in
            // Code to execute when a child is added under "Posts"
            postData.removeAll()
            postData2.removeAll()
            tableDataArray2.removeAll()


            for child in snapshot.children {
                let snap = child as! DataSnapshot
                let key = snap.key
                let value = String(describing: snap.value!)
                let rating = (value as NSString).integerValue

                postData.append(key)
                postData2.append(value)

                tableDataArray2.append(tableData(boothName: key, boothRating: rating))
                currentpostDataArray = postData
            }

            self.tableView.reloadData()


        })

    }


    private func setUpSearchBar() {
        searchBar.delegate = self
    }

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




    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)

        cell.textLabel?.text = currentpostDataArray[indexPath.row]
        cell.detailTextLabel?.text = postData2[indexPath.row] + " ♥"
        cell.detailTextLabel?.textColor = UIColor.red;
        return cell
    }


    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        switch searchBar.selectedScopeButtonIndex {
        case 0:
            selectedTab = 0
            searchArray.removeAll()
            searchArray = tableDataArray
            currentpostDataArray.removeAll()
            postData2.removeAll()
            if !searchText.isEmpty {
                for data in searchArray {
                    let item = data.boothName
                    if (item.lowercased().range(of: searchText.lowercased()) != nil)
                    {
                        currentpostDataArray.append(data.boothName)
                        let value = String(describing: data.boothRating)
                        postData2.append(value)
                    }
                }
            }
            else {
                loadDara()
            }
            self.tableView.reloadData()
        case 1:
            selectedTab = 1
            searchArray.removeAll()
            searchArray = tableDataArray2
            currentpostDataArray.removeAll()
            postData2.removeAll()
            if !searchText.isEmpty {
                for data in searchArray {
                    let item = data.boothName
                    if (item.lowercased().range(of: searchText.lowercased()) != nil)
                    {
                        currentpostDataArray.append(data.boothName)
                        let value = String(describing: data.boothRating)
                        postData2.append(value)
                    }
                }
            }
            else {
                loadDara2()
            }
            self.tableView.reloadData()
        default:
            break
        }
    }


    func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
        switch selectedScope {
        case 0:
            currentpostDataArray.removeAll()
            postData2.removeAll()
            for data in tableDataArray {
                currentpostDataArray.append(data.boothName)

                let value = String(describing: data.boothRating)
                postData2.append(value)
            }
            self.tableView.reloadData()

        case 1:
            currentpostDataArray.removeAll()
            postData2.removeAll()
            let sortedTableData = tableDataArray2.sorted(by: { $0.boothRating > $1.boothRating })
            for data in sortedTableData {
                currentpostDataArray.append(data.boothName)

                let value = String(describing: data.boothRating)
                postData2.append(value)
            }
            self.tableView.reloadData()

        default:
            break

        }
        tableView.reloadData()
    }

    func loadDara() {
        for data in tableDataArray {
            currentpostDataArray.append(data.boothName)

            let value = String(describing: data.boothRating)
            postData2.append(value)
        }

    }

    func loadDara2() {
        let sortedTableData = tableDataArray2.sorted(by: { $0.boothRating > $1.boothRating })
        for data in sortedTableData {
            currentpostDataArray.append(data.boothName)

            let value = String(describing: data.boothRating)
            postData2.append(value)
        }
    }

}

class tableData {
    var boothName: String
    var boothRating: Int
    init(boothName: String, boothRating: Int) {
        self.boothName = boothName
        self.boothRating = boothRating
    }
}

Answer 1

在视图控制器中声明一个指向选择了哪个段的变量

var selectedTab = 0

在selectedScopeButtonIndexDidChange中，根据选择更改为上述变量指定值：

func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
            switch selectedScope {
            case 0:
                selectedTab = 0
                currentpostDataArray.removeAll()
                postData2.removeAll()
                for data in tableDataArray {
                    currentpostDataArray.append(data.boothName)

                    let value = String(describing: data.boothRating)
                    postData2.append(value)
                }
                self.tableView.reloadData()

            case 1:
                selectedTab = 1
                currentpostDataArray.removeAll()
                postData2.removeAll()
                let sortedTableData = tableDataArray.sorted(by: { $0.boothRating > $1.b

oothRating })
            for data in sortedTableData {
                currentpostDataArray.append(data.boothName)

                let value = String(describing: data.boothRating)
                postData2.append(value)
            }
            self.tableView.reloadData()

        default:
            break

        }
        tableView.reloadData()
    }

在numberOfRowsInSection中，检查所选的细分并设置行数：

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            if selectedTab = 0 {
              return currentpostDataArray.count
            } else {
              if currentpostDataArray.count >= 10 {
                return 10
              } else {
                return currentpostDataArray.count
              }
            }
 }

Answer 2

在对 tableDataArray 进行排序后，您应该使用 tableDataArray

中的前10个元素创建一个数组

Answer 3

您需要在更改 segmentControl 的索引时实现逻辑。将标记变量设置为段的索引更改并再次重新加载表视图。在您的代码中，无论Segmentindex变为什么，您都会返回表格视图中的所有单元格。

你可以尝试这个，如果你感到困惑，请随时评论：

import Foundation
import UIKit
class SegmentViewController : UIViewController,UITableViewDelegate,UITableViewDataSource
{
    @IBOutlet weak var uiSegmentControl: UISegmentedControl!
    @IBOutlet weak var tableView: UITableView!
    var tag : Int = 1
    override func viewDidLoad() {
        super.viewDidLoad()
        self.tableView.delegate = self
        self.tableView.dataSource = self
    }


    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if tag == 1
        {  //return total count
            return 100
        }
        else if tag == 2
        {
            return 10
        }
        return 0
        }


    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = self.tableView.dequeueReusableCell(withIdentifier: "Cell") as! UITableViewCell
        cell.textLabel?.text = "CEll"
        return cell
    }


    @IBAction func didchange(_ sender: Any) {
        if uiSegmentControl.selectedSegmentIndex == 1
        {
          print("Segment 1 is selected")
            self.tag = 2
            self.tableView.reloadData()
        }
        else
        {
            print("Segment 2 is selected")
             self.tag = 1
            self.tableView.reloadData()

        }
    }
}

Answer 4

您需要自定义何时附加loadDara2功能的数据。

func loadDara2() {
    let sortedTableData = tableDataArray.sorted(by: { $0.boothRating > $1.boothRating })
    for data in sortedTableData {
        currentpostDataArray.append(data.boothName)

        let value = String(describing: data.boothRating)
          if (postData2.count != 10){
               postData2.append(value)
            }else {
              break
         }
    }
}

这会有所帮助。

Answer 5

创建分段控件的出口并连接它。

@IBOutlet weak var segment: UISegmentedControl!

现在用以下代码替换 numberOfRowsInSection 方法。

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return segment.selectedSegmentIndex == 0 ? currentpostDataArray.count : min(currentpostDataArray.count, 10)
}