当我点击indexpath.row == 0处的选择按钮或任何其他时，仅使用相应的＆＃34;会话标签值＆＃34;会改变，但在这里不会发生。它会改变下面的单元格值，即indexpath == 7或8，我认为这里是单元格的重用，所以我怎么能避免它。
我的代码如下所示。
1.UITableViewCell类：
import UIKit
class DemoTableViewCell: UITableViewCell {
@IBOutlet weak var mSelectButton: UIButton!
@IBOutlet weak var mDateLabel: UILabel!
@IBOutlet weak var mSessionLabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
ViewController类： -
导入UIKit
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var month_year = ""
var fromYear = ""
var toYear = ""
var monthYearList = ""
var monthYearListArray = [String]()
let picker : UIDatePicker = UIDatePicker()
var from_date = ""
var to_date = ""
//
var selectedTagValue = Int()
var aSheetValue = ""
var isFromActionSheet = Bool()
var isFromFinalClick = Bool()
var intArray = [Int]()
@IBOutlet weak var mTableView: UITableView!
// MARK:- ViewController Life Cycle Methods
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
self.printDatesBetweenInterval(self.dateFromString("2017-07-01"), self.dateFromString("2017-07-12"))
}
//MARK:- UITableViewDataSource and Delegate Methods
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return monthYearListArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "DemoTableViewCell")! as! DemoTableViewCell
cell.mDateLabel.text = monthYearListArray[indexPath.row]
if isFromActionSheet{
if indexPath.row == selectedTagValue{
cell.mSessionLabel.text = aSheetValue
isFromActionSheet = false
}
}
cell.mSelectButton.tag = indexPath.row
print("cell.mButtonOutlet.tag: \(cell.mSelectButton.tag)")
cell.mSelectButton.addTarget(self, action: #selector(ViewController.actionOnSelectButtonClick(_:)), for: .touchUpInside)
if isFromFinalClick{
if cell.mSessionLabel.text == "Full Day"{
self.intArray.append(1)
}else if cell.mSessionLabel.text == "First Half"{
self.intArray.append(2)
}else{
self.intArray.append(3)
}
}
return cell
}
// MARK:- IBAction Methods
func actionOnSelectButtonClick(_ sender: UIButton) {
let mButton : UIButton = sender
selectedTagValue = mButton.tag
print("selectedTagValue: \(selectedTagValue)")
isFromActionSheet = true
openActionSheet()
}
// Submit Button
@IBAction func actionOnSubmitButton(_ sender: Any) {
isFromFinalClick = true
mTableView.reloadData()
print("intArray list: \(intArray)")
}
// MARK:- Instance Methods
func openActionSheet() {
// 1
let optionMenu = UIAlertController(title: nil, message: "Select Session", preferredStyle: .actionSheet)
// 2
let fullDayAction = UIAlertAction(title: "Full Day", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
print("Full Day")
self.aSheetValue = "Full Day"
self.mTableView.reloadData()
})
let firstHalfAction = UIAlertAction(title: "First Half", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
print("First Half")
self.aSheetValue = "First Half"
self.mTableView.reloadData()
})
let secondHalfAction = UIAlertAction(title: "Second Half", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
print("Second Half")
self.aSheetValue = "Second Half"
self.mTableView.reloadData()
})
//
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: {
(alert: UIAlertAction!) -> Void in
print("Cancelled")
})
// 4
optionMenu.addAction(fullDayAction)
optionMenu.addAction(firstHalfAction)
optionMenu.addAction(secondHalfAction)
optionMenu.addAction(cancelAction)
// 5
self.present(optionMenu, animated: true, completion: nil)
}
// MARK:- Date_List Method
func printDatesBetweenInterval(_ startDate: Date, _ endDate: Date) {
var startDate = startDate
let calendar = Calendar.current
let fmt = DateFormatter()
fmt.dateFormat = "yyyy-MM-dd"
while startDate <= endDate {
print(fmt.string(from: startDate))
self.monthYearList = fmt.string(from: startDate)
print("self.monthYearList: \(self.monthYearList)")
fmt.dateFormat = "yyyy-MM-dd"
monthYearListArray.append(fmt.string(from: startDate))
startDate = calendar.date(byAdding: .day, value: 1, to: startDate)!
}
print("monthYearListArray: \(monthYearListArray)")
mTableView.reloadData()
}
func dateFromString(_ dateString: String) -> Date {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
return dateFormatter.date(from: dateString)!
}
}
答案 0 :(得分：6)
不要避免重复使用单元格，而是确保所有UI元素始终处于已定义的状态
if isFromActionSheet && indexPath.row == selectedTagValue{
cell.mSessionLabel.text = aSheetValue
isFromActionSheet = false
} else {
cell.mSessionLabel.text = [default value]
isFromActionSheet = [default value]
}
答案 1 :(得分：0)
正确的做法是，您需要始终在cellForRow中设置这些UI元素。
原因是UITableView没有准备用于显示的表视图单元格，直到用户尝试滚动到该位置（即用户试图查看该单元格时）。因此，重用单元格的想法是将一些单元格模板保留在重用位置，以便下次您的手机不需要再次从头创建所有内容。唯一需要做的就是再次将单元格设置为正确状态。这也将使滚动更加流畅。
通过设置UI元素，我的意思是每次调用cellForRow方法时都必须为单元格上的UI元素设置值。看看这段代码
if isFromActionSheet{//What if this if is not called? Your cell.mSessionLabel will not get set
if indexPath.row == selectedTagValue{//What if this if is not called? Your cell.mSessionLabel will not get set
cell.mSessionLabel.text = aSheetValue
isFromActionSheet = false
}
}
如果两个if语句中的任何一个不为真，那么单元格上的mSessionLabel将不会获得新值，并且可能会显示来自模板单元格的其他值。所以你必须在两个else语句中创建两个else语句add set mSessionLabel。