UITableViewCell 在滚动时重复并丢失其数据
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【中文标题】UITableViewCell 在滚动时重复并丢失其数据【英文标题】：UITableViewCell are repeating and lost its data while scrolling 【发布时间】：2017-07-23 04:16:52 【问题描述】：我创建了一个 Form ，我在其中使用了 Textfields 和 TextField Dropdown。当我滚动 TableView 文本字段值时，文本字段值会丢失，并且文本字段下拉值会自动设置为默认值。
这是我的代码：
enum TextFieldTags:Int
case ProspectName = 10, VisitDate, VisitType, Industry, Source, DissSummary, Requirements, FollowUpDate, AnticipatedDealValue, Probability, ExpectedClosingDate, Status, NextStep, Emp, Rev, AddressLine1, AddressLine2, Country, States, City, Zip, Mobile,Fax
var prospectName:String?, visitDate:String? , visitType:String?, industry:String?, source:String?, dissSummary:String?, requirements:String?, followUpDate:String?, anticipatedDealValue:String?, probability:String?, expectedClosingDate:String?, status:String?, nextStep:String?, emp:String?, rev:String?, addressLine1:String?, addressLine2:String?, country, statesVal:String?, cityVal:String?, zip:String?, mobile:String?,fax:String?
var currentLeadMaster:WizLeadMaster?
// MARK: - Section Data Structure
struct Section
var name: String!
var options: [Any]!
var collapsed: Bool!
var optionItem:[Any]!
var icon:UIImage!
init(name: String, options: [Any], collapsed: Bool = false,optionItem:[Any],icon:UIImage)
self.name = name
self.options = options
self.collapsed = collapsed
self.optionItem = optionItem
self.icon = icon
// MARK: - Properties
@IBOutlet weak var tblLeadDetail:UITableView?
var dataSource:NSArray = NSArray(objects: "Lead Summary","Address","Products","Contacts","Attachment","Follow Up","Remarks")
var sections = [Section]()
lazy var visitArr:NSArray =
let visitTypes = Handler.fetchLookUpOftype(type: LookUpType.enum_cRMVisittype)
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizLookUp
let dict = ["system":(visitModel.system! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
lazy var leadStatus:NSArray =
let visitTypes = Handler.fetchLookUpOftype(type: LookUpType.enum_cRMLeadStatus)
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizLookUp
let dict = ["system":(visitModel.system! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
lazy var leadSource:NSArray =
let visitTypes = Handler.fetchLookUpOftype(type: LookUpType.enum_cRMLeadsource)
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizLookUp
let dict = ["system":(visitModel.system! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
lazy var industries:NSArray =
let visitTypes = Handler.fetchLookUpOftype(type: LookUpType.enum_cRMCustomerType)
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizLookUp
let dict = ["system":(visitModel.system! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
lazy var countries:NSArray =
let visitTypes = Handler.countriesList()
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizCountryList
let dict = ["system":(visitModel.lable! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
lazy var states:NSArray =
let visitTypes = Handler.fetchLookUpOftype(type: LookUpType.enum_cRMTerritory)
var optionsArray = NSMutableArray(capacity: 0)
for visitType in visitTypes
let visitModel = visitType as! WizLookUp
let dict = ["system":(visitModel.system! as String),"value":(visitModel.value! as String)]
optionsArray.add(dict as NSDictionary)
return optionsArray as NSArray
()
func setStatesForCountry(_ country:String) -> Void
func filterValue(_ arr:NSArray,key:String) -> Any
let predicate = NSPredicate(format: "self == %@", key)
let filteredArr = arr.filtered(using: predicate)
if (filteredArr.count == 0)
return ""
return filteredArr[0]
// MARK: - ViewDidLoad
override func viewDidLoad()
super.viewDidLoad()
let barButtonItem = UIBarButtonItem(image:UIImage(named:"save1") , style: UIBarButtonItemStyle.done, target: self, action: #selector(saveLeadInfo))
navigationItem.rightBarButtonItem = barButtonItem
sections = [
Section(name: "Lead Summary", options: [["title":"Prospect Name","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.customer_name as Any,"tag":TextFieldTags.ProspectName.rawValue],
["title":"Visit Date","type":"date","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.visited_date as Any,"tag":TextFieldTags.VisitDate.rawValue],
["title":"Visit Type","type":"dropdown","options":visitArr.value(forKeyPath: "system") as! Array<String>,"value":filterValue(visitArr.value(forKeyPath: "value") as! NSArray, key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.visit_type)!),"tag":TextFieldTags.VisitType.rawValue],
["title":"Industry","type":"dropdown","options":industries.value(forKeyPath: "system"),"value":filterValue(industries.value(forKeyPath: "value") as! NSArray, key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.type)!),"tag":TextFieldTags.Industry.rawValue],
["title":"Source","type":"dropdown","options":leadSource.value(forKeyPath: "system"),"value":filterValue(leadSource.value(forKeyPath: "value") as! NSArray , key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.source)!),"tag":TextFieldTags.Source.rawValue],
["title":"Discussion Summary","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.summary_disc as Any,"tag":TextFieldTags.DissSummary.rawValue],
["title":"Requirements","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.requirements as Any ,"tag":TextFieldTags.Requirements.rawValue],
["title":"Follow-Up Date","type":"date","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.followup_date as Any,"tag":TextFieldTags.FollowUpDate.rawValue],
["title":"Anticipated Deal Value","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.anticipated_deal_value as Any,"tag":TextFieldTags.AnticipatedDealValue.rawValue],
["title":"Probabilty","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.probability as Any,"tag":TextFieldTags.Probability.rawValue],
["title":"Expected Closing Date","type":"date","value":currentLeadMaster?.expected_closing_date as Any,"tag":TextFieldTags.ExpectedClosingDate.rawValue],
["title":"Status","type":"dropdown","options":leadStatus.value(forKeyPath: "system"),"value":filterValue(leadStatus.value(forKeyPath: "value") as! NSArray, key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.status)!),"tag":TextFieldTags.Status.rawValue],
["title":"Next Step","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.next_activity_planned as Any,"tag":TextFieldTags.NextStep.rawValue],
["title":"Emp","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.no_of_emp as Any,"tag":TextFieldTags.Emp.rawValue],
["title":"Rev","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.annual_revenue as Any,"tag":TextFieldTags.Rev.rawValue]], collapsed: true, optionItem: [],icon:UIColor.clear.getImage(size: CGSize(width: 30, height: 30))),
Section(name: "Address", options: [["title":"Address Line 1","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline1 as Any ,"tag":TextFieldTags.AddressLine1.rawValue],
["title":"Address Line 2","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline2 as Any,"tag":TextFieldTags.AddressLine2.rawValue],
["title":"Select Country","type":"dropdown","options":countries.value(forKeyPath: "system") as! Array<String>,"value":filterValue(visitArr.value(forKeyPath: "value") as! NSArray, key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.visit_type)!),"tag":TextFieldTags.Country.rawValue],
["title":"Select States","type":"dropdown","options":visitArr.value(forKeyPath: "system") as! Array<String>,"value":filterValue(visitArr.value(forKeyPath: "value") as! NSArray, key: ((currentLeadMaster == nil) ? "":currentLeadMaster?.visit_type)!),"tag":TextFieldTags.States.rawValue],
["title":"Select City","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline2 as Any,"tag":TextFieldTags.City.rawValue],
["title":"Zip Code","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline2 as Any,"tag":TextFieldTags.Zip.rawValue],
["title":"Mobile","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline2 as Any,"tag":TextFieldTags.Mobile.rawValue],
["title":"Fax","type":"input","value":(currentLeadMaster == nil) ? "":currentLeadMaster?.addressline2 as Any,"tag":TextFieldTags.Fax.rawValue]
], collapsed: true, optionItem: [],icon:UIColor.clear.getImage(size: CGSize(width: 30, height: 30))),
Section(name: "Product", options: [], collapsed: true, optionItem: [],icon:UIImage.init(named: "add")!),
Section(name: "Contacts", options: [], collapsed: true, optionItem: [],icon:UIImage.init(named: "add")!),
Section(name: "Attachment", options: [], collapsed: true, optionItem: [],icon:UIImage.init(named: "attach")!),
]
let headerNib = UINib(nibName: "WizHeaderView", bundle: nil)
tblLeadDetail?.register(headerNib, forHeaderFooterViewReuseIdentifier: "headerLeads")
let textInputCell = UINib(nibName: "TextInputCell", bundle: nil)
tblLeadDetail?.register(textInputCell, forCellReuseIdentifier: "textinputcell")
let dropDownInputCell = UINib(nibName: "DropDownInputCell", bundle: nil)
tblLeadDetail?.register(dropDownInputCell, forCellReuseIdentifier: "dropDownInputCell")
let dropDownDateCell = UINib(nibName: "DropDownDateCell", bundle: nil)
tblLeadDetail?.register(dropDownDateCell, forCellReuseIdentifier: "dropDownDateCell")
tblLeadDetail?.reloadData()
func saveLeadInfo() -> Void
// MARK: - TableView Delegates & Datasource
func numberOfSections(in tableView: UITableView) -> Int
return sections.count
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
let optionsArray = sections[section].options
return optionsArray!.count
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
let optionsArray = sections[indexPath.section].options
let dict = optionsArray?[indexPath.row] as! Dictionary<String,Any>
if (dict["type"] as! String == "dropdown")
let cell = tableView.dequeueReusableCell(withIdentifier: "dropDownInputCell") as! DropDownInputCell
cell.txtInput.isOptionalDropDown = false
cell.txtInput.itemList = dict["options"] as! [String]
cell.lblText.text = dict["title"] as? String
cell.txtInput.selectedItem = dict["value"] as? String
cell.txtInput.tag = (dict["tag"] as? NSInteger)!
cell.backgroundColor = UIColor.clear
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.delegate = self
return cell
else if (dict["type"] as! String == "input")
let cell = tableView.dequeueReusableCell(withIdentifier: "textinputcell") as! TextInputCell
cell.lblText.text = dict["title"] as? String
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.backgroundColor = UIColor.clear
cell.txtInput.text = dict["value"] as? String
cell.txtInput.tag = (dict["tag"] as? NSInteger)!
cell.delegate = self
return cell
else
let cell = tableView.dequeueReusableCell(withIdentifier: "dropDownDateCell") as! DropDownDateCell
cell.lblText.text = dict["title"] as? String
cell.txtInput.dropDownMode = IQDropDownMode.datePicker
if dict["value"] as? String == ""
cell.txtInput.setDate(Date(), animated: true)
else
cell.txtInput.selectedItem = dict["value"] as? String
cell.txtInput.tag = (dict["tag"] as? NSInteger)!
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.backgroundColor = UIColor.clear
cell.delegate = self
return cell
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
tableView.deselectRow(at: indexPath, animated: true)
// if indexPath.row == 0
// performSegue(withIdentifier: "leadsummary", sender:nil)
//
// else
// performSegue(withIdentifier: "leadaddress", sender:nil)
//
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView?
let header = tableView.dequeueReusableHeaderFooterView(withIdentifier: "headerLeads") as? WizHeaderView ?? WizHeaderView(reuseIdentifier: "headerLeads")
header.delegate = self
header.lblLeadSummary.text = sections[section].name
header.btnArrowButton.setImage(sections[section].icon, for: UIControlState.normal)
header.setCollapsed(sections[section].collapsed)
header.section = section
return header
func toggleSection(_ header: WizHeaderView, section: Int)
let collapsed = !sections[section].collapsed
// Toggle collapse
sections[section].collapsed = collapsed
header.setCollapsed(collapsed)
// Adjust the height of the rows inside the section
tblLeadDetail?.beginUpdates()
for i in 0 ..< sections[section].options.count
tblLeadDetail?.reloadRows(at: [IndexPath(row: i, section: section)], with: .automatic)
tblLeadDetail?.endUpdates()
@IBAction func placeOrder(_ sender: Any)
let placeOrder = MainStoryBoard.instantiateViewController(withIdentifier: "PlaceOrder")
navigationController?.pushViewController(placeOrder, animated: true)
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat
return 35.0
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat
return 10.0
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat
return sections[(indexPath as NSIndexPath).section].collapsed! ? 0 : 70.0
func cellTextField(_with TextField: IQDropDownTextField, didSelectItem item: String?)
switch TextField.tag
case TextFieldTags.VisitType.rawValue:
visitType = item
break
case TextFieldTags.Industry.rawValue:
industry = item
break
case TextFieldTags.Source.rawValue:
source = item
break
case TextFieldTags.Status.rawValue:
status = item
break
case TextFieldTags.Country.rawValue:
country = item
break
case TextFieldTags.States.rawValue:
statesVal = item
break
default: break
func cellTextFieldDidEndEditing(_with textField: UITextField)
switch textField.tag
case TextFieldTags.ProspectName.rawValue:
prospectName = textField.text
break
case TextFieldTags.DissSummary.rawValue:
dissSummary = textField.text
break
case TextFieldTags.Requirements.rawValue:
requirements = textField.text
break
case TextFieldTags.AnticipatedDealValue.rawValue:
anticipatedDealValue = textField.text
break
case TextFieldTags.Probability.rawValue:
probability = textField.text
break
case TextFieldTags.NextStep.rawValue:
nextStep = textField.text
break
case TextFieldTags.Emp.rawValue:
emp = textField.text
break
case TextFieldTags.Rev.rawValue:
rev = textField.text
break
case TextFieldTags.AddressLine1.rawValue:
addressLine1 = textField.text
break
case TextFieldTags.AddressLine2.rawValue:
addressLine2 = textField.text
break
case TextFieldTags.City.rawValue:
cityVal = textField.text
break
case TextFieldTags.Mobile.rawValue:
mobile = textField.text
break
case TextFieldTags.Fax.rawValue:
fax = textField.text
break
case TextFieldTags.Zip.rawValue:
zip = textField.text
break
default: break
func stringFromDate(_ date:Date) -> String
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
return formatter.string(from: date)
func cellTextFieldDate(_with textField: IQDropDownTextField, didSelect date: Date?)
switch textField.tag
case TextFieldTags.VisitDate.rawValue:
visitDate = stringFromDate(date!)
break
case TextFieldTags.FollowUpDate.rawValue:
followUpDate = stringFromDate(date!)
break
case TextFieldTags.ExpectedClosingDate.rawValue:
expectedClosingDate = stringFromDate(date!)
break
default: break
extension UIColor
func getImage(size: CGSize) -> UIImage
let renderer = UIGraphicsImageRenderer(size: size)
return renderer.image(actions: rendererContext in
self.setFill()
rendererContext.fill(CGRect(x: 0, y: 0, width: size.width, height: size.height))
)
【问题讨论】：
您是否尝试过在您的UITableViewCells 中覆盖prepareForReuse() 并在出列之前清除其数据？：S
您是否实现了 UITextField 的委托方法（如 textFieldDidBeginEditing）以将您在特定文本字段中收到的任何输入存储到您的数据源？
【参考方案1】：
使用UITableView with reusable cell identifier 时，您必须在编辑完成后将UITextField 或任何其他输入字段的输入存储到您用来填充所有单元格的数据源中。因为可重用单元管理内存本身以绘制所有控件，所以当您滚动表格视图时，不能保证您的数据保持原样。
【讨论】：
【参考方案2】：在这个if - else 表达式中
if dict["value"] as? String == ""
cell.txtInput.setDate(Date(), animated: true)
else
cell.txtInput.selectedItem = dict["value"] as? String
您正在根据字典值设置两个不同 UI 元素。 随着单元格的重复使用，这些 UI 状态将一直保留到下次更改为止。
您必须确保将每个 UI 元素设置为已定义状态以避免意外行为，因此您也需要设置其他 UI 元素。例如（[default value] 只是一个占位符）。
if dict["value"] as? String == ""
cell.txtInput.setDate(Date(), animated: true)
cell.txtInput.selectedItem = [default value]
else
cell.txtInput.setDate([default value], animated: [default value])
cell.txtInput.selectedItem = dict["value"] as? String
如果没有唯一的default value，则必须向数据源添加属性以保持日期和所选项目的当前状态。
关于文本字段，您必须在更改文本后更新数据源，因为在cellForRow 中，文本字段总是从数据源更新。
并且 - 一如既往 - 不要在 Swift 中使用 NS(Mutable)Array 和 NS(Mutable)Dictionary。您丢弃了重要的类型信息，可变集合类型与 Swift 原生类型无关。最后，您可以删除switch 表达式中的所有break 行（default 之后除外）。它们在 Swift 中是多余的。
【讨论】：
dict["value"] 不能为空。因为我已经在我的结构中设置了值 如果不能为空，为什么还要检查？ 你可以看到问题的代码，我没有对cellForRowAtIndexPath中的dict["value"]做任何检查。 你拥有：在最后的else 子句中（创建DropDownDateCell）。
不工作！我做了你上面建议的所有事情以上是关于UITableViewCell 在滚动时重复并丢失其数据的主要内容，如果未能解决你的问题，请参考以下文章
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