iOS 8.3 中在使用 textView.textContainer.maximumNumberOfLines = 10
时有两个需要注意的问题。
请参考我的 gist。
textView.attributedText = originalContent
let lineLimit = 10
textView.isEditable = true
textView.isScrollEnabled = false
textView.textContainerInset = .zero // default is (8, 0, 8, 0)
textView.textContainer.maximumNumberOfLines = lineLimit // Important condition
textView.textContainer.lineBreakMode = .byTruncatingTail
// two incomplete methods, which do NOT work in iOS 8.3
// size.width可能比maxSize.width小 ————遗憾的是 iOS 8.3 上此方法无视maximumNumberOfLines参数,所以得借助于UILabel
// size.width may be less than maxSize.width, ---- Do NOT work in iOS 8.3, which disregards textView.textContainer.maximumNumberOfLines
// let size = textView.sizeThatFits(maxSize)
// 遗憾的是 iOS 8.3 上此方法失效了,得借助于UILabel
// Does not work in iOS 8.3
// let size = textView.layoutManager.usedRectForTextContainer(textView.textContainer).size
// Suggested method: use a temperary label to get its size
let label = UILabel(); label.attributedText = originalContent
let size = label.textRect(forBounds: CGRect(origin: .zero, size: maxSize), limitedToNumberOfLines: lineLimit).size
textView.frame.size = size
这里是声明
fileprivate weak var textView: UITextView!
在这里调用您的setupview函数
override func viewDidLoad() {
super.viewDidLoad()
setupViews()
}
在这里进行设置
fileprivate func setupViews() {
let textView = UITextView()
textView.translatesAutoresizingMaskIntoConstraints = false
textView.text = "your text here"
textView.font = UIFont.poppinsMedium(size: 14)
textView.textColor = UIColor.brownishGrey
textView.textAlignment = .left
textView.isEditable = false
textView.isScrollEnabled = false
textView.textContainerInset = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
self.view.addSubview(textView)
self.textView = textView
setupConstraints()
}
在这里设置约束条件
fileprivate func setupConstraints() {
NSLayoutConstraint.activate([
textView.topAnchor.constraint(equalTo: view.topAnchor, constant: 20),
textView.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 20),
textView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -20),
textView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20),
textView.heightAnchor.constraint(greaterThanOrEqualToConstant: 150),
])
}
textView
。请从视图didload()
中调用此函数:func textViewDidChange(_ textView: UITextView) {
let esmitated = CGSize(width: txtView.frame.width, height: .infinity)
let esmitatedSize = txtView.sizeThatFits(esmitated)
self.heghtConstraint.constant = esmitatedSize.height
}