换行符不适用于 tableFooterView 中的 UILabel

Question

I habe a tableView with a footerView . It should display a simple label.

In my ViewController, in viewDidLoad , I assign the tableFooterView like so:

let footerView = MyFooterView(frame: CGRect(x: 0, y: 0, width: tableView.frame.width, height: 0))
tableView.tableFooterView = footerView

MyFooterView is a UIView with a single label. The label setup looks like so:

label.font = someFont
label.adjustsFontForContentSizeCategory = true
label.textColor = .black
label.numberOfLines = 0
label.text = "my super looooooong label that should break some lines but it doesn't."
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
addSubview(label)
NSLayoutConstraint.activate([
    label.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 40),
    label.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -40),
    label.topAnchor.constraint(equalTo: self.topAnchor, constant: 20),
    label.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -20)
])

In order to get AutoLayout to work with MyFooterView , I call this method inside UIViewControllers viewDidLayoutSubviews :

func sizeFooterToFit() {
    if let footerView = self.tableFooterView {
        footerView.setNeedsLayout()
        footerView.layoutIfNeeded()

        let height = footerView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
        var frame = footerView.frame
        frame.size.height = height
        footerView.frame = frame

        self.tableFooterView = footerView
    }
}

Problem: The lines in the label do not break. I get the following result:

What can I do so that the label has multiple lines? AutoLayout is working thanks to the method sizeFooterToFit . The only thing is that the labels height is only as high as a single line.

Answer 1

HERE is the way how you can achieve it for tableHeaderView and with your case you just need to add below code in your UIViewController class

override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()
    tbl.updateHeaderViewHeight()
}

And Helper extension

extension UITableView {
    func updateHeaderViewHeight() {
        if let header = self.tableFooterView {
            let newSize = header.systemLayoutSizeFitting(CGSize(width: self.bounds.width, height: 0))
            header.frame.size.height = newSize.height
        }
    }
}

And remove

func sizeFooterToFit() {
    if let footerView = self.tableFooterView {
        footerView.setNeedsLayout()
        footerView.layoutIfNeeded()

        let height = footerView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
        var frame = footerView.frame
        frame.size.height = height
        footerView.frame = frame

        self.tableFooterView = footerView
    }
}

Above code.

And result will be: