ios - 如何使用字典中的值保持按钮状态
问题描述
我UITableView
从带有标签的字典中填充了一个。用户可以将标签从 ViewController 添加到另一个 ViewController。每个标签都有一个属性remoteID
。当用户按下+
按钮添加标签时,按钮的颜色会更改-
为所选标签。到目前为止一切正常。问题是当我从 MainViewController 返回到 TagsViewController 时,按钮的状态没有保存。现在所有标签按钮显示+
。你能帮我保存按钮的状态(标题)吗?在这里,我用我的问题创建了一个小项目:https://github.com/tygruletz/AppendTagsToCells
这是我的代码:
class Tag{
var remoteID: Int
var categoryID: Int
var name: String
var color: String
init(remoteID: Int, categoryID: Int, name: String, color: String) {
self.remoteID = remoteID
self.categoryID = categoryID
self.name = name
self.color = color
}
}
主VC:
class ChecklistVC: UIViewController {
@IBOutlet weak var questionsTableView: UITableView!
//Properties
lazy var itemSections: [ChecklistItemSection] = {
return ChecklistItemSection.checklistItemSections()
}()
var lastIndexPath: IndexPath!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
questionsTableView.reloadData()
}
}
extension ChecklistVC: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let itemCategory = itemSections[section]
return itemCategory.checklistItems.count
}
func numberOfSections(in tableView: UITableView) -> Int {
return itemSections.count
}
// Set the header of each section
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
let checklistItemCategory = itemSections[section]
return checklistItemCategory.name.uppercased()
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "checklistCell", for: indexPath) as! ChecklistCell
let itemCategory = itemSections[indexPath.section]
let item = itemCategory.checklistItems[indexPath.row]
cell.delegate = self
cell.configCell(item)
cell.vehicleCommentLabel.text = item.vehicleComment
cell.trailerCommentLabel.text = item.trailerComment
let sortedTagNames = item.vehicleTags.keys.sorted(by: {$0 < $1}).compactMap({ item.vehicleTags[$0]})
print("Sorted tag names: \(sortedTagNames.map {$0.name})")
let joinedTagNames = sortedTagNames.map { $0.name}.joined(separator: ", ")
cell.tagNameLabel.text = joinedTagNames
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 150
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goChecklistAddComment" {
let addCommentVC = segue.destination as! ChecklistAddCommentVC
addCommentVC.delegate = self
}
if segue.identifier == "goChecklistAddTag" {
let addTagVC = segue.destination as! ChecklistAddTagVC
addTagVC.delegate = self
addTagVC.addedTags = itemSections[lastIndexPath.section].checklistItems[lastIndexPath.row].vehicleTags
}
}
}
// Receive Tags from ChecklistAddTagVC using the Delegate Pattern
extension ChecklistVC: ChecklistAddTagVCDelegate{
func receiveAddedTags(tags: [Int : Tag]) {
let item = self.itemSections[self.lastIndexPath.section].checklistItems[self.lastIndexPath.row]
item.vehicleTags = tags
}
}
标签VC:
protocol ChecklistAddTagVCDelegate {
func receiveAddedTags(tags: [Int: Tag])
}
class ChecklistAddTagVC: UIViewController {
// Interface Links
@IBOutlet weak var tagsTableView: UITableView!
// Properties
var tagsDictionary: [Int: Tag] = [:]
var addedTags: [Int: Tag] = [:]
var delegate: ChecklistAddTagVCDelegate?
var indexPathForBtn: IndexPath!
override func viewDidLoad() {
super.viewDidLoad()
tagsTableView.tableFooterView = UIView()
tagsDictionary = [
1: Tag(remoteID: 1, categoryID: 1, name: "Tag1", color: "red"),
2: Tag(remoteID: 2, categoryID: 1, name: "Tag2", color: "blue"),
3: Tag(remoteID: 3, categoryID: 1, name: "Tag3", color: "orange"),
4: Tag(remoteID: 4, categoryID: 1, name: "Tag4", color: "black")
]
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
print("Added tags: \(addedTags.map {$1.name})")
setupButtons()
tagsTableView.reloadData()
}
}
extension ChecklistAddTagVC: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tagsDictionary.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "defectAndDamageTagCell", for: indexPath) as! ChecklistAddTagCell
cell.configCell()
cell.delegate = self
cell.tagNameLabel.text = tagsDictionary[indexPath.row + 1]?.name.capitalized
indexPathForBtn = indexPath
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 60
}
}
extension ChecklistAddTagVC: ChecklistAddTagCellDelegate{
// When the user press Add Tag then will be added in a dictionary and sent to ChecklistVC using a callback closure.
func addTagBtnPressed(button: UIButton, tagLabel: UILabel) {
let buttonPosition: CGPoint = button.convert(CGPoint.zero, to: tagsTableView)
let indexPath = tagsTableView.indexPathForRow(at: buttonPosition)
let indexPathForBtn: Int = indexPath?.row ?? 0
let tag: Tag = tagsDictionary[indexPathForBtn + 1] ?? Tag(remoteID: 0, categoryID: 0, name: String(), color: String())
if button.currentTitle == "+"{
button.setTitle("-", for: UIControl.State.normal)
tagLabel.textColor = UIColor.orange
// Add selected tag to Dictionary when the user press +
addedTags[tag.remoteID] = tag
}
else{
button.setTitle("+", for: UIControl.State.normal)
tagLabel.textColor = UIColor.black
// Delete selected tag from Dictionary when the user press -
addedTags.removeValue(forKey: tag.remoteID)
}
// Send the Dictionary to ChecklistVC
if delegate != nil{
delegate?.receiveAddedTags(tags: addedTags)
}
print("\n ****** UPDATED DICTIONARY ******")
print(addedTags.map {"key: \($1.remoteID) - name: \($1.name)"})
}
// Setup the state of the buttons and also the color of the buttons to be orange if that Tag exist in `addedTags` dictionary.
func setupButtons(){
for eachAddedTag in addedTags {
if eachAddedTag.value.remoteID == tagsDictionary[1]?.remoteID {
print(eachAddedTag)
}
}
}
}
这是我的错误的捕获:
感谢您阅读本文!
解决方案
首先你需要一个数组而不是字典
tagsArr = [
Tag(remoteID: 1, categoryID: 1, name: "Tag1", color: "red"),
Tag(remoteID: 2, categoryID: 1, name: "Tag2", color: "blue"),
Tag(remoteID: 3, categoryID: 1, name: "Tag3", color: "orange"),
Tag(remoteID: 4, categoryID: 1, name: "Tag4", color: "black")
]
那么vehicleTags
propety应该是[Tag]()
,知道它是否存在或者不使用cellForRowAt
insideChecklistAddTagVC
let tag = tagsArr[indexPath.row].remoteID
let res = addedTags.map { $0.remoteID }
if res.contains(tag) {
// tag exists color it
}
else {
// not here
}
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