Swift: UITextView&UITextField 限制字数和输入内容

public extension JKPOP where Base: UITextView {
  // MARK: 3.1、限制字数的输入(提示在：- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;方法里面调用)
  /// 限制字数的输入
  /// - Parameters:
  ///   - range: 范围
  ///   - text: 输入的文字
  ///   - maxCharacters: 限制字数
  ///   - regex: 可输入内容(正则)
  /// - Returns: 返回是否可输入
  func inputRestrictions(shouldChangeTextIn range: NSRange, replacementText text: String, maxCharacters: Int, regex: String?) -> Bool {
      guard !text.isEmpty else {
          return true
      }
      guard let oldContent = self.base.text else {
          return false
      }
      if let _ = self.base.markedTextRange {
          /*
           let selectedRange = textView.markedTextRange
           let beginning = textView.beginningOfDocument
           let selectionStart = selectedRange.start
           let selectionEnd = selectedRange.end
           let location = textView.offset(from: beginning, to: selectionStart)
           let length = textView.offset(from: selectionStart, to: selectionEnd)
           print("location：\(location) length：\(length)")
           let selectText = textView.text(in: selectedRange)
           print("高亮部分的文字：\(selectText ?? "高亮没有文字")")
           print("有range-----------：YES \(selectedRange) 开始：\(selectedRange.start) 内容：\(oldContent) 长度：\(oldContent.count) 新的内容：\(text) 长度：\(text.count) 是否包含emoji表情：\(text.fb.containsEmoji()) range：\(range)")
           */
          // print("🚀有range---------内容：\(oldContent) 长度：\(oldContent.count) 新的内容：\(text) 长度：\(text.count) range：\(range)")
           // 有高亮
          if range.length == 0 {
              // 联想中
              return oldContent.count + 1 <= maxCharacters
          } else {
              // 正则的判断
              if let weakRegex = regex, !JKRegexHelper.match(text, pattern: weakRegex) {
                  return false
              }
              // 联想选中键盘
              let allContent = oldContent.jk.sub(to: range.location) + text
              if allContent.count > maxCharacters  {
                  let newContent = allContent.jk.sub(to: maxCharacters)
                  // print("content1：\(allContent) content2：\(newContent)")
                  self.base.text = newContent
                  return false
              }
          }
      } else {
          guard !text.jk.isNineKeyBoard() else {
              return true
          }
          // 正则的判断
          if let weakRegex = regex, !JKRegexHelper.match(text, pattern: weakRegex) {
              return false
          }
          // print("没有range---------：NO 内容：\(oldContent) 长度：\(oldContent.count) 新的内容：\(text) 长度：\(text.count) range：\(range)")
          // 2、如果数字大于指定位数，不能输入
          guard oldContent.count + text.count <= maxCharacters else {
              return false
          }
      }
      return true
  }
}

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    return textView.inputRestrictions(shouldChangeTextIn: range, replacementText: text, maxCharacters: maxCharacters, regex: regex)
}
func textViewDidChange(_ textView: UITextView) {
    print("字符数量：\(textView.text.count > maxCharacters ? maxCharacters : textView.text.count)")
}