UITextView

1.准确计算UITextView的高度

@IBOutlet weak var detailAddressTextView: UITextView!{
        didSet{
            detailAddressTextView.delegate = self
            detailAddressTextView.textContainerInset = .zero
            let padding = detailAddressTextView.textContainer.lineFragmentPadding;
            detailAddressTextView.textContainerInset = UIEdgeInsets(top: 0, left: -padding, bottom: 0, right: -padding)
        }
    }

func calculateHeight(text:String?)-> CGFloat{
        let attr = [NSAttributedString.Key.font: addressTextField.font]
        let width = KScreenWidth - 118
        let maxSize: CGSize = CGSize(width:width, height: CGFloat(MAXFLOAT))
        let option = NSStringDrawingOptions.usesLineFragmentOrigin.rawValue|NSStringDrawingOptions.usesFontLeading.rawValue
        let height = text?.boundingRect(with: (maxSize), options: NSStringDrawingOptions(rawValue: option), attributes: attr as [NSAttributedString.Key : Any], context: nil).size.height ?? 0
        return  (height < 79 ? 79 : height) + 10
    }

extension AddAddressViewController: UITextViewDelegate{
    func textViewDidChange(_ textView: UITextView) {
        textHeightLayout.constant = calculateHeight(text: textView.text)
        self.view.setNeedsLayout()
    }
}

UITextField

1.准确限制UITextField的输入位数

nameTextField.addTarget(self, action: #selector(nameTextFieldDidChangeValue), for: .editingChanged)
@objc func nameTextFieldDidChangeValue(_ sender: UITextField) {
        guard let name = sender.text else{ return }
        if name.count >= 10 {           //名字的位数不能超过11位
            if sender.markedTextRange != nil {
                return
            }
            sender.text = name.substring(from: 0, to: 9)
        }
    }

2.限制UITextField的只能输入中文

import UIKit

class ChineseTextField: UITextField {
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupUI()
    }
    
    func setupUI() {
        NotificationCenter.default.addObserver(self, selector: #selector(textFiledEditChanged(not:)), name: UITextField.textDidChangeNotification, object: nil)
    }
    @objc func textFiledEditChanged(not:Notification) {
        //非markedText才继续往下处理
        guard let _:UITextRange = self.markedTextRange else {
        guard let end = self.selectedTextRange?.end else { return }
            //当前光标的位置
            let cursorPosition = self.offset(from: self.endOfDocument, to: end)
            let pattern = "[^\\u4E00-\\u9FA5]"
            //替换后的字符串（过滤调非中文字符）
            let str = self.text!.pregReplace(pattern: pattern, with: "")
            self.text = str
            
            //让光标停留在正确位置
            guard let targetPostion = self.position(from: self.endOfDocument,
                                                    offset: cursorPosition) else{ return }
            self.selectedTextRange = self.textRange(from: targetPostion,
                                                              to: targetPostion)
            return
        }
    }
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
}

extension String {
    //使用正则表达式替换
    func pregReplace(pattern: String, with: String,
                     options: NSRegularExpression.Options = []) -> String {
        let regex = try! NSRegularExpression(pattern: pattern, options: options)
        return regex.stringByReplacingMatches(in: self, options: [],
                                              range: NSMakeRange(0, self.count),
                                              withTemplate: with)
    }
}

3.限制UITextField的只能输入数字和英文

1.定义能输入的字符串
let ALPHANUM = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
2.设置代理
fileNumberTextField.delegate = self
3.实现代理方法
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let cs = CharacterSet(charactersIn: ALPHANUM).inverted
        let filtered = string.components(separatedBy: cs).joined(separator: "")
        return string == filtered
    }

2.计算文本高度里面(包含有"\n"换行符)

 //给定宽度，计算文本的高度

static var attr:[NSAttributedString.Key : Any] {
        let paraph = NSMutableParagraphStyle()
        paraph.maximumLineHeight = 24
        paraph.minimumLineHeight = 24
        let attr: [NSAttributedString.Key : Any] = [NSAttributedString.Key.font: UIFont(name: kPingFangSCRegular, size: 16) ?? UIFont.systemFont(ofSize: 16),NSAttributedString.Key.paragraphStyle:paraph,NSAttributedString.Key.foregroundColor:kLoginDarkGrayColor]
        return attr
    }

    func calculateWidthWith(width: CGFloat)-> CGFloat {
        //文字最大尺寸
        let maxSize: CGSize = CGSize(width: width, height: CGFloat(MAXFLOAT))
        let options = NSStringDrawingOptions.usesLineFragmentOrigin.rawValue|NSStringDrawingOptions.usesFontLeading.rawValue
        let replaceStr = "\n"
        let contentString = (dialoContent as NSString).replacingOccurrences(of: replaceStr, with: "")
        let count = (dialoContent.count - contentString.count) / replaceStr.count
        let option = NSStringDrawingOptions.init(rawValue:options )
        let dialoContentAtt = NSAttributedString(string: contentString, attributes: MessageNormalCell.attr)
        
        let replaceH = dialoContentAtt.boundingRect(with: maxSize, options: option, context: nil).size.height
        return replaceH + CGFloat(count * 24)
    }