问题描述
以下是我更新tableview单元格内视图高度的代码
override func layoutSubviews() {
super.layoutSubviews()
layout()
}
fileprivate func layout() {
rootFlexContainer.frame.size.width = frame.width - 20
rootFlexContainer.flex.layout(mode: .adjustHeight)
if(rootFlexContainer.frame.height != 0) {
tagsHeight.constant = rootFlexContainer.frame.height
}
}
虽然这在我滚动之前不会反映出来，即重新创建单元格。如何更新视图的 TableViewCell 内的约束？
这是整个tableviewcell代码
import UIKit
import FlexLayout
import SDWebImage
class StoreListTableViewCell: UITableViewCell {
@IBOutlet weak var menuLbl: UILabel!
@IBOutlet weak var menuView: UIView!
@IBOutlet weak var cellBgview: UIView!
@IBOutlet weak var storeImg: UIImageView!
@IBOutlet weak var storeLocation: UILabel!
@IBOutlet weak var storeTitle: UILabel!
@IBOutlet weak var cellContainer: UIView!
@IBOutlet weak var stackView: UIStackView!
@IBOutlet weak var tagsHeight: NSLayoutConstraint!
var storeImgStr = ""
var storeTitleStr = ""
var storeLocationStr = ""
var score : Double = 0.0
var tagsstr = ""
var isMenuAvailble = 0
var retailerTags: [String]?
var cashbackString = ""
fileprivate let rootFlexContainer = UIView()
@IBOutlet weak var tagsView: UIView!
@IBOutlet weak var ratingBtn: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
self.layoutIfNeeded()
cellBgview.clipsToBounds = true
cellBgview.layer.cornerRadius = 5
cellContainer.layer.shadowColor = UIColor.lightGray.cgColor
cellContainer.layer.shadowOpacity = 0.5
cellContainer.layer.shadowRadius = 5.0
cellContainer.layer.shadowOffset = CGSize(width: 0,height: 2)
cellContainer.backgroundColor = UIColor.clear
cellContainer.layer.cornerRadius = 5.0
cellContainer.layer.borderColor = UIColor.white.cgColor
cellContainer.layer.borderWidth = 0.5
ratingBtn.layer.borderWidth = 1
ratingBtn.layer.cornerRadius = 5
tagsView.addSubview(rootFlexContainer)
//cellContainer.layer.shadowPath = UIBezierPath(rect: cellBgview.bounds).cgPath
}
func setSetupStoreUI() {
if isMenuAvailble == 1 {
menuView.isHidden = false
menuView.layer.cornerRadius = 10
} else {
menuView.isHidden = true
}
storeTitle.text = storeTitleStr
// storeTitle.sizetoFit()
storeLocation.text = storeLocationStr
//storeLocation.sizetoFit()
//.filter{ $0.name != " " }
//storeImg.sd_imageIndicator = SDWebImageActivityIndicator.gray
storeImg.backgroundColor = UIColor.hexStringToUIColor(hex: AppStrings.placeHolderColor)
if let url = URL(string: storeImgStr.encoded),!(storeImgStr.isEmpty) {
self.storeImg.sd_setimage(with: url)
}
menuLbl.text = AppLocalString.PREORDER_TEXT.localized()
menuLbl.font = FontStyle.ProximaNovaBold(size: 12)
storeTitle.font = FontStyle.ProximaNovaSemibold(size: 14)
storeLocation.font = FontStyle.ProximaNovaRegular(size: 12)
storeLocation.textColor = .gray
// ratingBtn.isHidden = (score == 0)
ratingBtn.setTitle(score == 0 ? "-" : String(format: "%.1f",score),for: .normal)
ratingBtn.backgroundColor = UIColor.hexStringToUIColor(hex: Utility.getratingColor(rating: score))
ratingBtn.layer.borderColor = UIColor.hexStringToUIColor(hex: Utility.getratingColor(rating: score)).cgColor
rootFlexContainer.subviews.forEach({ $0.removeFromSuperview() })
//tagsView.willRemoveSubview(rootFlexContainer)
//rootFlexContainer.frame = tagsView.frame
//tagsView.addSubview(rootFlexContainer)
rootFlexContainer.flex.direction(.row).wrap(.wrap).alignSelf(.auto).justifyContent(.start).paddingRight(2).define { (flex) in
for i in 0..<((retailerTags?.count ?? 0) > 3 ? 3 : (retailerTags?.count ?? 0)) {
let nameLabel = UIButton()
nameLabel.isUserInteractionEnabled = false
nameLabel.setTitle((retailerTags?[i] ?? "").trim(),for: .normal)
nameLabel.setTitleColor(.black,for: .normal)
nameLabel.titleLabel?.font = FontStyle.ProximaNovaRegular(size: 11)
nameLabel.contentEdgeInsets = UIEdgeInsets(top: 1.5,left: 4,bottom: 1.5,right:4)
nameLabel.layer.borderColor = UIColor.hexStringToUIColor(hex: AppStrings.grayBorderColor).cgColor
nameLabel.layer.cornerRadius = 8
nameLabel.layer.borderWidth = 1.0
nameLabel.sizetoFit()
flex.addItem(nameLabel).margin(2)
}
if cashbackString != "" {
let cashbackLabel = UIButton()
cashbackLabel.backgroundColor = UIColor.hexStringToUIColor(hex: AppStrings.orangeCashbackColor)
cashbackLabel.isUserInteractionEnabled = false
cashbackLabel.setTitle(cashbackString,for: .normal)
cashbackLabel.setTitleColor(.black,for: .normal)
cashbackLabel.titleLabel?.font = FontStyle.ProximaNovaRegular(size: 10)
cashbackLabel.contentEdgeInsets = UIEdgeInsets(top: 1.5,left: 5,right: 5)
cashbackLabel.layer.cornerRadius = 5
cashbackLabel.layer.borderWidth = 0
cashbackLabel.sizetoFit()
flex.addItem(cashbackLabel).margin(2)
}
}
rootFlexContainer.flex.layout()
if retailerTags?.count ?? 0 == 0 {
tagsView.isHidden = true
} else {
tagsView.isHidden = false
}
}
override func layoutSubviews() {
super.layoutSubviews()
layout()
}
fileprivate func layout() {
rootFlexContainer.frame.size.width = frame.width - 20
rootFlexContainer.flex.layout(mode: .adjustHeight)
if(rootFlexContainer.frame.height != 0) {
tagsHeight.constant = rootFlexContainer.frame.height
}
}
override func setSelected(_ selected: Bool,animated: Bool) {
super.setSelected(selected,animated: animated)
// Configure the view for the selected state
}
}
以下是故事板的视图层次结构
解决方法
一些观察 -
1. layoutIfNeeded()
awakeFromNib() 调用
override func awakeFromNib() {
super.awakeFromNib()
/*
self.layoutIfNeeded() // Not Necessary,Remove it.
*/
// No other changes to current implementation
}
2.不需要以下内容，请将其删除。
/* Not necessary,Remove it.
override func layoutSubviews() {
super.layoutSubviews()
layout()
}
fileprivate func layout() {
rootFlexContainer.frame.size.width = frame.width - 20
rootFlexContainer.flex.layout(mode: .adjustHeight)
if(rootFlexContainer.frame.height != 0) {
tagsHeight.constant = rootFlexContainer.frame.height
}
}
*/
3.在填充所有详细信息的方法中，进行以下更改
func setSetupStoreUI() {
// No changes to current implementation
/* Remove this,we will update later
rootFlexContainer.flex.layout()
*/
if retailerTags?.count ?? 0 == 0 {
tagsView.isHidden = true
} else {
tagsView.isHidden = false
}
// Copied as is from `layout()`
rootFlexContainer.frame.size.width = frame.width - 20
rootFlexContainer.flex.layout(mode: .adjustHeight)
if (rootFlexContainer.frame.height != 0) {
tagsHeight.constant = rootFlexContainer.frame.height
}
// do a manual layout (on contentView,NOT self)
self.contentView.layoutIfNeeded()
}
你必须告诉表格视图控制器你的单元格高度已经改变了。
最常见的方法是协议/委托模式或（swift 首选）闭包。
例如...
在您的单元格类中：
class MyTableViewCell: UITableViewCell {
// "callback" closure
var cellHeightChanged: (()->())?
// whatever happens that you need to change the cell height
func heightChanged() -> Void {
tagsHeight.constant = rootFlexContainer.frame.height
cellHeightChanged?()
}
}
然后，在您的控制器中，在 cellForRowAt 中：
cell.cellHeightChanged = {
tableView.performBatchUpdates(nil,completion: nil)
}