如何使用uistackview根据自定义的xib高度设置动态uitablviewcell高度

Question

我无法将UITableViewcell设置为具有动态高度。

我有一个自定义的xib，结构如下， 并已将堆栈视图的前导，尾随和顶部约束添加到其超级视图

class fieldView: UIView {
let kCONTENT_XIB_NAME = "form_field_view"

@IBOutlet weak var contectView: UIView!
@IBOutlet weak var fieldDesc: UILabel!
@IBOutlet weak var fieldInput: customTextField!

var required: Bool?

override init(frame: CGRect) {
    super.init(frame: frame)
    commonInit()

}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    commonInit()
}

func commonInit() {
    Bundle.main.loadNibNamed(kCONTENT_XIB_NAME, owner: self, options: nil)
    addSubview(contectView)
    contectView.frame = self.bounds
    contectView.autoresizingMask = [.flexibleHeight, .flexibleWidth]
    fieldInput.isScrollEnabled = false
}

}

在tableView cellForRowAt中，我创建自定义视图并将其添加到每个UITableViewCell

cell.contentView.addSubview(fieldView)
NSLayoutConstraint(item: fieldView, attribute: NSLayoutConstraint.Attribute.leading, relatedBy: NSLayoutConstraint.Relation.equal, toItem: cell.contentView, attribute: NSLayoutConstraint.Attribute.leadingMargin, multiplier: 1.0, constant: 10.0).isActive = true
        NSLayoutConstraint(item: fieldView, attribute: NSLayoutConstraint.Attribute.trailing, relatedBy: NSLayoutConstraint.Relation.equal, toItem: cell.contentView, attribute: NSLayoutConstraint.Attribute.trailingMargin, multiplier: 1.0, constant: 100.0).isActive = true
        NSLayoutConstraint(item: fieldView, attribute: NSLayoutConstraint.Attribute.top, relatedBy: NSLayoutConstraint.Relation.equal, toItem: cell.contentView, attribute: NSLayoutConstraint.Attribute.topMargin, multiplier: 1.0, constant: 0.0).isActive = true
        NSLayoutConstraint(item: fieldView, attribute: NSLayoutConstraint.Attribute.bottom, relatedBy: NSLayoutConstraint.Relation.equal, toItem: cell.contentView, attribute: NSLayoutConstraint.Attribute.bottomMargin, multiplier: 1.0, constant: 0.0).isActive = true
return cell

对于tableView

override func viewDidLoad() {
    super.viewDidLoad()

    fieldTable.rowHeight = UITableView.automaticDimension
    fieldTable.estimatedRowHeight = 200.0
    }
}

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    if (expanded) {
        return (UITableView.automaticDimension)
    }else{
        return 0
    }
}

但是实际结果是这样的

我认为UIStackView的高度发生了变化，但其superview却没有发生变化，这使得tableviewcell也没有发生变化

我该如何解决？

Answer 1

最后我弄清楚了这个问题

只需添加这两行

self.tableView.beginUpdates()
self.tableView.endUpdates()

在文本字段内容更改时调用

Answer 2

首先，您必须计算UILabel的行数

printf "(H) heads or (T) tails"
read user_choice
if [ $user_choice != H ] && [ $user_choice != T ]; then
  echo invalid choice defaulting to heads
  user_choice=H=1
  user_choice=T=0
fi
#value of 1 is heads, 2 is Tails
computer_choice=$(($RANDOM% 2 + 1))
if [ $computer_choice == 1 ]; then
  echo computer chooses tails
fi
if [ $computer_choice == 1 ] && [ $user_choice = H ]; then
  echo you win!
else
  echo you lose
  if [ $computer_choice == 2 ] && [ $user_choice = T ]; then
    echo you win!
    echo computer chooses heads
  else
    echo you lose
  fi
fi

否则，您可以扩展以计算标签的最大行数

 NSInteger lineCount = 0;
 CGSize textSize = CGSizeMake(yourLabel.frame.size.width, MAXFLOAT);
 int rHeight = lroundf([yourLabel sizeThatFits:textSize].height);
 int charSize = lroundf(yourLabel.font.lineHeight);
 lineCount = rHeight/charSize;
 NSLog(@"No of lines: %i",lineCount);

使用它：

extension UILabel {
    func calculateMaxLines() -> Int {
        let maxSize = CGSize(width: frame.size.width, height: CGFloat(Float.infinity))
        let charSize = font.lineHeight
        let text = (self.text ?? "") as NSString
        let textSize = text.boundingRect(with: maxSize, options: .usesLineFragmentOrigin, attributes: [NSAttributedString.Key.font: font], context: nil)
        let linesRoundedUp = Int(ceil(textSize.height/charSize)) 
        return linesRoundedUp
    }    
}

现在设置标签每一行的高度

let lineCount = YourLabel. calculateMaxLines