问题描述
我正在尝试实现文本的布局，然后是图像（图像的高度基于长宽比计算），然后是文本，依此类推。问题是我将视图添加到视图中的stackview随机压缩了视图，有时imageviews在文本消失的某个时候消失了，它没有一致的行为。
我在uitableview和uicolletion视图上都尝试过，结果是相同的。是否将上述观点的组合视为此类用例的最佳实践？如果不是这样的话，最好的做法是什么？
class MyStackyView: UIStackView {
// Main variables
weak var videoPlayerDelegate: AVPlayerViewDelegate?
private var avVideoPlayersVC: [AVPlayerViewController] = []
var content: [Content]! {
didSet {
contentCombined = Utility.shared.combinetoNew(contents: content)
}
}
private var contentCombined: [Content] = [] {
didSet {
populatePostContent()
}
}
var contentViews: [UIView] = [] // Holds the views created
override init(frame: CGRect) {
super.init(frame: frame)
configureView()
}
required init(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
deinit {
print("DiaryPostView:: Deinitalized")
}
private func configureView() {
axis = .vertical
distribution = .fill
alignment = .fill
spacing = 0
}
}
//用于填充帖子内容的扩展名 扩展MyStackyView {
private func populatePostContent() {
for content in contentCombined {
if content.isMedia {
addMedia(content)
} else {
addText(content.text)
}
}
}
}
//扩展以添加所需的视图 扩展MyStackyView {
private func addText(_ text: String?,place: MediaPlace = .center) {
let textView = generateDefaultTextView()
//let parsedText = HTMLParser.shared.parseHTMLToAttributed(string: text ?? "") // fix font issue
switch place {
case .center:
append(textView)
contentViews.append(textView)
}
textView.text = text
// لما استخدم ال parsedtext مرة النص بطلع مع الfont و مرة لا
}
private func addMedia(_ content: Content) {
let avPlayerVC = getAVPlayerViewController()
let mediaView = generateDefaultMediaView()
switch content.getRawPlace() {
case .center:
append(mediaView)
contentViews.append(mediaView)
addText(content.text)
NetworkManager().downloadMedia(content.img!,into: mediaView,avPlayerViewController: avPlayerVC) {
}
}
}
}
扩展名MyStackyView {
private func generateDefaultTextView() -> UILabel {
let textView = UILabel()
textView.backgroundColor = .clear
textView.numberOfLines = 0
textView.font = UIFont.customFont(.openSans,.regular,.title1,17)
return textView
}
private func generateDefaultHorizontalStack() -> UIStackView {
let horizontalStack = UIStackView()
horizontalStack.axis = .horizontal
horizontalStack.distribution = .fill
horizontalStack.alignment = .fill
return horizontalStack
}
private func generateDefaultMediaView() -> MediaSliderView {
let mediaSliderView = MediaSliderView()
return mediaSliderView
}
private func getAVPlayerViewController() -> AVPlayerViewController? {
videoPlayerDelegate?.getAVPlayerVC?()
}
func deallocateAVPlayers() {
for player in avVideoPlayersVC {
player.removeFromParent()
}
avVideoPlayersVC.removeAll()
}
}
我在uitableviewcell中初始化该类的变量，然后添加这些约束
contentView.addSubview(MyStackyView)
MyStackyView.topAnchor.constraint(equalTo: contentView.topAnchor,constant: 8).isActive = true
MyStackyView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor,constant: -8).isActive = true
MyStackyView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor,constant: 16).isActive = true
MyStackyView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor,constant: -16).isActive = true
请在可能的情况下为我提供一些指导。
谢谢，感谢您的帮助
解决方法
这是一个（相当）基本的例子。
我们将使用这样的数据结构：
struct VarDevStruct {
var first: String = ""
var second: String = ""
var imageName: String = ""
}
单元格类具有一个包含以下内容的垂直堆栈视图：
- 多行标签
- 水平堆栈视图
- 具有80x80的图像视图和标签
- 多行标签
如果数据结构中的任何元素为空字符串，则将单元格中的相应元素设置为隐藏。
首先，结果：
向下滚动到几行包含不同数据的行：
并旋转：
这是完整的代码...里面有很多注释，因此应该清楚代码在做什么。
数据结构
struct VarDevStruct {
var first: String = ""
var second: String = ""
var imageName: String = ""
}
单元格类
class VarDevCell: UITableViewCell {
let firstLabel = UILabel()
let secondLabel = UILabel()
let imgView = UIImageView()
let imgNameLabel = UILabel()
let vStack = UIStackView()
let hStack = UIStackView()
override init(style: UITableViewCell.CellStyle,reuseIdentifier: String?) {
super.init(style: style,reuseIdentifier: reuseIdentifier)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
func commonInit() -> Void {
// stack view properties
vStack.axis = .vertical
vStack.alignment = .fill
vStack.distribution = .fill
vStack.spacing = 8
vStack.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(vStack)
// let's use the default cell margins
let g = contentView.layoutMarginsGuide
NSLayoutConstraint.activate([
// constrain stack view to all 4 sides
vStack.topAnchor.constraint(equalTo: g.topAnchor),vStack.leadingAnchor.constraint(equalTo: g.leadingAnchor),vStack.trailingAnchor.constraint(equalTo: g.trailingAnchor),vStack.bottomAnchor.constraint(equalTo: g.bottomAnchor),])
// subview properties
// background colors to make it easy to see the frames
firstLabel.backgroundColor = .yellow
secondLabel.backgroundColor = .green
imgView.backgroundColor = .red
imgNameLabel.backgroundColor = .cyan
// multi-line labels
firstLabel.numberOfLines = 0
secondLabel.numberOfLines = 0
imgNameLabel.textAlignment = .center
// image view defaults to scaleToFill
// let's set it to scaleAspectFit
imgView.contentMode = .scaleAspectFit
// horizontal stack view
hStack.axis = .horizontal
hStack.alignment = .center
hStack.distribution = .fill
hStack.spacing = 8
// add subviews to horizontal stack view
hStack.addArrangedSubview(imgView)
hStack.addArrangedSubview(imgNameLabel)
// let's fill the vertical stack view with
// label
// hStack with 80x80 imageview and label with image name
// label
vStack.addArrangedSubview(firstLabel)
vStack.addArrangedSubview(hStack)
vStack.addArrangedSubview(secondLabel)
// set image view width and height
imgView.widthAnchor.constraint(equalToConstant: 80.0).isActive = true
imgView.heightAnchor.constraint(equalTo: imgView.widthAnchor,multiplier: 1.0).isActive = true
}
func fillData(_ vdStruct: VarDevStruct) -> Void {
firstLabel.text = vdStruct.first
secondLabel.text = vdStruct.second
imgNameLabel.text = vdStruct.imageName
// does our data have an image name?
if !vdStruct.imageName.isEmpty {
if #available(iOS 13.0,*) {
if let img = UIImage(systemName: vdStruct.imageName) {
imgView.image = img
}
} else {
// Fallback on earlier versions
if let img = UIImage(named: vdStruct.imageName) {
imgView.image = img
}
}
}
// hide elements that we don't need in this cell
firstLabel.isHidden = vdStruct.first.isEmpty
secondLabel.isHidden = vdStruct.second.isEmpty
hStack.isHidden = vdStruct.imageName.isEmpty
}
}
控制器类
class VarDevTableViewController: UITableViewController {
var myData: [VarDevStruct] = []
override func viewDidLoad() {
super.viewDidLoad()
// register cell class for reuse
tableView.register(VarDevCell.self,forCellReuseIdentifier: "cell")
// generate some sample data
myData = makeSampleData()
}
override func viewWillTransition(to size: CGSize,with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size,with: coordinator)
coordinator.animate(alongsideTransition: nil,completion: {
_ in
// make sure table re-calculates row heights
UIView.setAnimationsEnabled(false)
self.tableView.performBatchUpdates(nil,completion: nil)
UIView.setAnimationsEnabled(true)
})
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
return myData.count
}
override func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell",for: indexPath) as! VarDevCell
cell.fillData(myData[indexPath.row])
return cell
}
func makeSampleData() -> [VarDevStruct] {
var a: [VarDevStruct] = []
// 15 sample data elements
for i in 1...15 {
let d = VarDevStruct(first: "This is the text for the first label in row: \(i).",second: "This will be a longer string to be used as the text for the second label in row \(i) (long enough to make sure we're getting some word wrapping).",imageName: "\(i).square.fill")
a.append(d)
}
// change some of the sample data for variations
// (arrays are zero-based)
// fifth row: no first label
a[4].first = ""
a[4].second = "This row has no First label text."
// sixth row: no image
a[5].first = "This row has no image."
a[5].imageName = ""
// seventh row: no second label
a[6].first = "This row has no second label."
a[6].second = ""
// eigth row: no image or second label
a[7].first = "This row has no image,and has no second label. The next row (9) has image only."
a[7].imageName = ""
a[7].second = ""
// ninth row: image only
a[8].first = ""
a[8].second = ""
// tenth row: first label with mutliple lines
a[9].first = "One\nTwo\nThree\nFour"
a[9].second = "This row has embedded newline chars in the text of the first label."
return a
}
}