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[英]How to add padding inside a UITableViewCell with self-sizing cells?
[英]How to create dynamic self-sizing height UITableViewCell in swift?
嘿,我有一個 tableview 控制器,我想用標簽和 ImageViews 創建動態單元格高度。 我嘗試了類似下面的方法,但它對我不起作用。 代碼錯誤在哪里。 任何的想法 ?
class NotificationsPageController: UITableViewController{
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(NotificationCell.self, forCellReuseIdentifier: notCell)
view.backgroundColor = .black
tableView.estimatedRowHeight = 60
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension
}
override func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 60
}
class NotificationCell: UITableViewCell {
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
backgroundColor = UIColor(red: 18/255, green: 18/255, blue: 18/255, alpha: 1)
setNotificationAnchors()
}
fileprivate func setNotificationAnchors() {
addSubview(notiType)
notiType.anchor(top: topAnchor, left: leftAnchor, bottom: nil, right: rightAnchor, paddingTop: 4, paddingLeft: 6, paddingBottom: 0, paddingRight: 20, width: 0, height: 0)
//notiType.centerYAnchor.constraint(equalTo: notiImage.centerYAnchor).isActive = true
addSubview(notiImage)
notiImage.anchor(top: nil, left: nil, bottom: nil, right: rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 4, width: 0, height: 0)
notiImage.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
首先,我強烈建議您了解約束和自動布局的工作原理。 您發布的代碼表明您正在使用.anchor(top:left:bottom:right:...)
類型的“約束助手”這一事實表明您還不了解它。
所以,這里有一個簡單的例子。 請注意,這不是一個完整的實現,但它應該讓您朝着正確的方向前進:
class NotificationCell: UITableViewCell {
let notiType: UILabel = {
let v = UILabel()
v.translatesAutoresizingMaskIntoConstraints = false
v.numberOfLines = 0
return v
}()
let notiImage: UIImageView = {
let v = UIImageView()
v.translatesAutoresizingMaskIntoConstraints = false
return v
}()
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
backgroundColor = UIColor(red: 18/255, green: 18/255, blue: 18/255, alpha: 1)
setNotificationAnchors()
}
fileprivate func setNotificationAnchors() {
contentView.addSubview(notiType)
contentView.addSubview(notiImage)
let g = contentView.layoutMarginsGuide
NSLayoutConstraint.activate([
// constrain label Top, Leading, Bottom to contentView margins
notiType.topAnchor.constraint(equalTo: g.topAnchor, constant: 0.0),
notiType.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 0.0),
notiType.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: 0.0),
// constrain image view Right and centerY to contentView margins
notiImage.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: 0.0),
notiImage.centerYAnchor.constraint(equalTo: g.centerYAnchor, constant: 0.0),
// guessing square (1:1 ratio) image view, 24 x 24
notiImage.widthAnchor.constraint(equalToConstant: 24.0),
notiImage.heightAnchor.constraint(equalTo: notiImage.widthAnchor),
// leave 8-pts space between label and image view
notiType.trailingAnchor.constraint(equalTo: notiImage.leadingAnchor, constant: -8.0),
])
// during development, so we can easily see the element frames
notiType.backgroundColor = .cyan
notiImage.backgroundColor = .red
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class ExampleTableViewController: UITableViewController {
let notCell = "notCell"
let theData: [String] = [
"Single line label.",
"This lable will have enough text that it will need to wrap onto multiple lines.",
"Another single line cell.",
"Here is a description of a table view cell: Defines the attributes and behavior of cells in a table view. You can set a table cell's selected-state appearance, support editing functionality, display accessory views (such as a switch control), and specify background appearance and content indentation.",
"This is the fifth row.",
]
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(NotificationCell.self, forCellReuseIdentifier: notCell)
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return theData.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: notCell, for: indexPath) as! NotificationCell
cell.notiType.text = theData[indexPath.row]
// set image here...
//cell.notiImage.image = ...
return cell
}
}
結果 - 多行標簽(青色背景)和 24x24 圖像(紅色背景):
順便說一句......關於這個的分步教程可以在很多很多地方找到 - 有點難以認為你搜索過並且找不到這樣的東西。
請按照以下步驟操作:
在 ViewDidLoad 中添加以下幾行
tableView.dataSource = self
tableView.delegate = self
// Set automatic dimensions for row height
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = UITableViewAutomaticDimension
在XIB
或Cell
如果您有標簽更新numberOLines = 0
並使lineBreakMode = truncateTail
將top
、 bottom
、 right
和left
約束更新到其superView
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