我对 UICollection 视图列表的 separatorLayoutGuide 有疑问。我看到了这篇文章，明白我需要重写函数 updateConstraints() 以更新分隔符布局指南。像这样...
override func updateConstraints() {
super.updateConstraints()
separatorLayoutGuide.leadingAnchor.constraint(equalTo: otherView.leadingAnchor, constant: 0.0).isActive = true
}
我可以看到单元格的前导锚和分离向导的前导锚之间的微小空间，如下图所示，我想修复它。（像单元格的左侧）
但是，问题是，我使用本文创建了一个自定义集合视图列表单元格，并且无法更改导致自定义视图前导的 separatorLayoutGuide。我添加了customListCell.separatorLayoutGuide.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true为了将 separatorLayoutGuide 的前导定位到 customView 的前导，我得到了
"UILayoutGuide:0x2822d8b60'UICollectionViewListCellSeparatorLayoutGuide'.leading"> and <NSLayoutXAxisAnchor:0x280e9cac0 "ContentView:0x15960db90.leading"> because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.'
错误。完成研究后，我想我没有为 separatorLayoutGuide 添加子视图，但即使我向自定义视图添加子视图，应用程序也会崩溃。使用自定义 UIView 时，有没有办法更改分隔符指南的前导锚点？
class CustomListCell: UICollectionViewListCell {
var item: TestItem?
override func updateConfiguration(using state: UICellConfigurationState) {
// Create new configuration object
var newConfiguration = ContentConfiguration().updated(for: state)
newConfiguration.name = item.name
newConfiguration.state = item.state
// Set content configuration
contentConfiguration = newConfiguration
}
}
struct ContentConfiguration: UIContentConfiguration, Hashable {
var name: String?
var state: String?
func makeContentView() -> UIView & UIContentView {
return ContentView(configuration: self)
}
func updated(for state: UIConfigurationState) -> Self {
guard let state = state as? UICellConfigurationState else {
return self
}
// Updater self based on the current state
let updatedConfiguration = self
if state.isSelected {
print("is selected")
} else {
print("is deselected")
}
return updatedConfiguration
}
}
class ContentView: UIView, UIContentView {
let contentsView = UIView()
let customListCell = CustomListCell()
lazy var titleLabel: UILabel = {
let label = UILabel()
label.text = ""
return label
}()
lazy var statusLabel: UILabel = {
let label = UILabel()
label.text = ""
return label
}()
lazy var symbolImageView: UIImageView = {
let imageView = UIImageView()
imageView.contentMode = .scaleAspectFit
return imageView
}()
init(configuration: ContentConfiguration) {
// Custom initializer implementation here.
super.init(frame: .zero)
setupAllViews()
apply(configuration: configuration)
}
override func updateConstraints() {
super.updateConstraints()
customListCell.separatorLayoutGuide.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
private var currentConfiguration: ContentConfiguration!
var configuration: UIContentConfiguration {
get {
currentConfiguration
}
set {
guard let newConfiguration = newValue as? ContentConfiguration else {
return
}
apply(configuration: newConfiguration)
}
}
func setupAllViews() {
// add subviews and add constraints
}
func apply(configuration: ContentConfiguration) {
}
}