我试图在 UICollectionView 中显示数据，它的工作方式与我在整个应用程序中所做的完全一样，但由于某种原因，它在这种情况下不起作用：
这是理解问题所需的代码：
一些控制器：
func showContactsView(sender: RoundButton) -> Void {
DispatchQueue.main.async {
self.someView = SomeView()
self.view.addSubview(self.someView)
self.someView.setSomeViewViewConstraints(container:
self.view)
self.someView.alpha = 0.0
self.someView.contactsCollectionView.delegate = self
self.someView.contactsCollectionView.dataSource = self
self.someView.tabControlCallbacks["contacts"] = self.searchContacts
}
}
控制器初始化包含 UICollectionView 的视图。这部分由自动布局和约束处理，我没有问题。它还继承自 UIColleCtionViewDelegate 和 UICollectionViewDataSource。：
class SomeController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate
视图初始化 collectionView 并由 SegmentedControl 显示，它完美地工作：
private func initCollectionViews() {
let layout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
layout.itemSize = CGSize(width: 50, height: 50)
contactsCollectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
contactsCollectionView.backgroundColor = UIColor.black.withAlphaComponent(0.6)
contactsCollectionView.showsVerticalScrollIndicator = false
contactsCollectionView.showsHorizontalScrollIndicator = false
contactsCollectionView.register(AModelCollectionViewCell.self, forCellWithReuseIdentifier: "ContactsSelectModelCell")
contactsCollectionView.translatesAutoresizingMaskIntoConstraints = false
// Constraints to add when view is set dynamically
contactsCollectionViewConstraints["leading"] = NSLayoutConstraint(item: contactsCollectionView, attribute: .leading, relatedBy: .equal, toItem: self, attribute: .leading, multiplier: 1.0, constant: 0.0)
contactsCollectionViewConstraints["trailing"] = NSLayoutConstraint(item: self, attribute: .trailing, relatedBy: .equal, toItem: contactsCollectionView, attribute: .trailing, multiplier: 1.0, constant: 0.0)
contactsCollectionViewConstraints["top"] = NSLayoutConstraint(item: tabControl, attribute: .bottom, relatedBy: .equal, toItem: contactsCollectionView, attribute: .top, multiplier: 1.0, constant: 0.0)
contactsCollectionViewConstraints["bottom"] = NSLayoutConstraint(item: self, attribute: .bottom, relatedBy: .equal, toItem: contactsCollectionView, attribute: .bottom, multiplier: 1.0, constant: 0.0)
}
并且分段控件显示的值发生了变化：
func cleanViews() {
if self.contactsCollectionView.superview != nil {
self.contactsCollectionView.removeFromSuperview()
}
if self.favoritesCollectionView.superview != nil {
self.favoritesCollectionView.removeFromSuperview()
}
}
func bounce() {
self.cleanViews()
switch self.actualControl {
case -1:
break
case 0:
// Some code
case 1:
self.addSubview(self.contactsCollectionView)
for constraint in self.contactsCollectionViewConstraints {
self.addConstraint(constraint.value)
}
if let callback = self.tabControlCallbacks["contacts"]! {
callback()
}
default:
fatalError("Unknown control")
}
}
// Selectors UISegmentedControl
func valueChanged(sender: UISegmentedControl) {
if sender.selectedSegmentIndex == actualControl {
tabControl.isMomentary = true
sender.selectedSegmentIndex = -1
tabControl.isMomentary = false
}
actualControl = sender.selectedSegmentIndex
DispatchQueue.main.async {
self.bounce()
}
}
如您所见，我正在设置从控制器到视图的回调，以便对我的网络执行操作并获取要在 collectionView 上显示的数据。以下是控制器中的方法：
//Collection Views Actions/Callbacks for selectContactsView
func searchContacts() -> Void {
let params : [String:Any] = [
"id" : "-1",
"name_begin" : ""
]
self.network?.get(......, callback: afterSearchContacts)
}
func afterSearchContacts() -> Void {
DispatchQueue.main.async {
self.contactsSearchResults.removeAll()
let usersData : [[String:Any]] = self.network?.lastResponse!["users"] as! [[String:Any]]
let groupsData : [[String:Any]] = self.network?.lastResponse!["groups"] as! [[String:Any]]
for userData in usersData {
self.contactsSearchResults.append(User(fromData: userData))
}
for groupData in groupsData {
self.contactsSearchResults.append(Group(fromData: groupData))
}
self.contactsView.contactsCollectionView.reloadData()
}
}
reloadData 不起作用。在解释哪些部分有效，哪些无效之前，这里是代表和数据源的方法：
//MARK: - UICollectionViewDataSource
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
switch self.contactsView.actualControl {
case 1:
if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ContactsSelectModelCell", for: indexPath) as? AModelCollectionViewCell {
cell.model = contactsSearchResults[indexPath.item]
cell.fillCell()
return cell
}
case 0:
//some Code
return cell
}
default:
print("Unknown cell type")
}
fatalError("Unknown cell type")
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
let count = collectionView == contactsView.contactsCollectionView ? contactsSearchResults.count : favoritesSearchResults.count
return count
}
//MARK: - UICollectionViewFlowLayoutDelegate
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 50.0, height: 50.0)
}
我有一个自定义集合视图单元格，它正在处理其他集合视图，所以没问题。当我进行注册时，我还负责区分所有不同 CollectionViews 的标识符。在这种情况下，当我使用断点时，部分中的项目数> 0，但是当我在网络设置 contactsSearchResult 后在主线程中执行 reloadData 时，它永远不会通过 collectionView cellForItemAt。
任何的想法？