具有大小类的自定义UITableViewCells中的多行UILabel - iOS 8和Swift

Question

我遇到了iOS 8 beta 4(以及beta 5)的问题,这是UILabel未显示UITableViewCells中的所有文本.我使用自调整单元格来制作这个,并为所有设备使用一个故事板.

这是我在iPhone上得到的: -

代码: -

ViewController.swift

@IBOutlet var tableView: UITableView!

override func viewDidLoad() {
    super.viewDidLoad()

    self.tableView.registerClass(TableViewCell.self, forCellReuseIdentifier: "cell")

    self.tableView.estimatedRowHeight = 200
    self.tableView.rowHeight = UITableViewAutomaticDimension
}


func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
    let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as TableViewCell


    switch indexPath.row {
    case 0:
        cell.label.text  = "hello hello hello hellohellohellohellohello hello hello hello hello hello hello hello hellohellohello hellohello hellohellohellohellohello hello hello hello hello hello hello hello hello hello hello hello hello hellohellohello hello hello hello"
    case 1:
        cell.label.text  = "doesn'twork doesn'tworkdoesn't work doesn'twork doesn'tworkdoesn't work doesn'twork doesn'twork doesn't workdoesn't workdoesn'twork doesn'twork doesn't workdoesn't workdoesn't workdoesn'twork "
    case 2:
        cell.label.text  = "baims baimsbaimsbaims baimsbaimsbaimsbaims baims baimsbaims baimsbaimsbaimsbaims baimsbaims baims baimsbaimsbaims baimsbaims baims baimsbaimsbaimsbaims baimsbaims baimsbaims baimsbaims"
    default:
        cell.label.text  = "hello hello hello hellohellohellohellohello hello hello hello hello hello hello hello hellohellohello hellohello hellohellohellohellohello hello hello hello hello hello hello hello hello hello hello hello hello hellohellohello hello hello hello"
    }


    cell.setNeedsUpdateConstraints()
    cell.updateConstraintsIfNeeded()

    return cell
}

TableViewCell.swift

var label : UILabel!
var didUpdateConstraints = false

override init(style: UITableViewCellStyle, reuseIdentifier: String) {

    self.label = UILabel()
    self.label.textColor     = self.label.tintColor
    self.label.numberOfLines = 0

    self.label.setTranslatesAutoresizingMaskIntoConstraints(false)

    super.init(style: style, reuseIdentifier: reuseIdentifier)

    self.contentView.addSubview(self.label)
}

override func updateConstraints() {
    if !self.didUpdateConstraints {

        self.contentView.addConstraint(NSLayoutConstraint(item: self.label, attribute: .Leading, relatedBy: .Equal, toItem: self.contentView, attribute: .Leading, multiplier: 1, constant: 20))

        self.contentView.addConstraint(NSLayoutConstraint(item: self.label, attribute: .Trailing, relatedBy: .Equal, toItem: self.contentView, attribute: .Trailing, multiplier: 1, constant: 20))

        self.contentView.addConstraint(NSLayoutConstraint(item: self.label, attribute: .Bottom, relatedBy: .Equal, toItem: self.contentView, attribute: .Bottom, multiplier: 1, constant: 10))

        self.contentView.addConstraint(NSLayoutConstraint(item: self.label, attribute: .Top, relatedBy: .Equal, toItem: self.contentView, attribute: .Top, multiplier: 1, constant: 13))


        self.didUpdateConstraints = true
    }

    super.updateConstraints()
}

这是我的故事板: -

我认为这是beta 4中的一个错误,但它应该在beta 5中修复,因为发行说明说:

修正了测试版5:当多线标签的宽度因某些视图的layoutMargins的变化而发生变化时,标签的内在内容大小应该是无效的.因此,布局可能会意外地截断标签(或文本视图).///解决方法:layoutMargins正在更改的视图应覆盖layoutMarginsDidChange并将invalidateIntrinsicContentSize发送到标签.

Answer 1

您通过约束在表格视图上添加了相当大的边距，这是到边缘的距离。如果将此距离设置为 8 或Standard，则此距离将消失。这应该也可以解决高度问题TableViewCell，如果没有，请查看以下代码：

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    let label = // Get the label from the cell here
    return label.frame.size.height + 16 // Assuming you have 2 constraints on top & bottom, each 8
}