如何在swift中保持字符串上的属性组合

Question

我有一个需要设置属性的字符串。属性（粗体、斜体、删除线、下划线）被单独添加，但它们并没有与字符串保持完整。我想知道如何用字符串保持不同的属性不变，然后根据需要将它们一一删除。

Bold - 

   if textBold == true {
                            let string = text
                            let attributes: [NSAttributedString.Key: Any] = [
                                .font: UIFont.boldSystemFont(ofSize: 25)
                            ]
                            let attributedString = NSAttributedString(string: string, attributes: attributes)
                            modifiedString = attributedString
                            text_View.attributedText = modifiedString

                            text_View.sizeToFit()
                            databaseHandlerObj.editLabelData(textProjectId: fetchTextProjectId, text_Id: fetchTextId, text: modifiedString.string)
                        }

Italic - 
        if textItalic == true {

                            text_View.sizeToFit()
                            let string = text
                            
                            let attributes: [NSAttributedString.Key: Any] = [
                                .font: UIFont.italicSystemFont(ofSize: CGFloat(fontSize))
                            ]
                            let attributedString = NSAttributedString(string: string, attributes: attributes)
                            self.modifiedString = attributedString
                            text_View.attributedText = modifiedString
                            
                            databaseHandlerObj.editLabelData(textProjectId: fetchTextProjectId, text_Id: fetchTextId, text: modifiedString.string)
                        }

Underline -
   if textUnderline == true {
                            text_View.sizeToFit()
                            let string = text
                            let attributedString = NSMutableAttributedString.init(string: string)
                            attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: 1, range:
                                                            NSRange.init(location: 0, length: attributedString.length))
                            self.modifiedString = attributedString
                            text_View.attributedText = modifiedString
                            
                            databaseHandlerObj.editLabelData(textProjectId: fetchTextProjectId, text_Id: fetchTextId, text: modifiedString.string)
                        }
                        

Strikethrough - 
      if textStrikethrough == true {
                            text_View.sizeToFit()
                            let string = text
                            let attributeString: NSMutableAttributedString =  NSMutableAttributedString(string: string)
                            attributeString.addAttribute(NSAttributedString.Key.strikethroughStyle, value: 2, range: NSMakeRange(0, attributeString.length))
                            self.modifiedString = attributeString
                            text_View.attributedText = modifiedString
                            databaseHandlerObj.editLabelData(textProjectId: fetchTextProjectId, text_Id: fetchTextId, text: modifiedString.string)
                        }

Answer 1

在属性字典上添加条件。

let string = text
var attributes: [NSAttributedString.Key: Any] = [:]

if bold {
    attributes[.font] = UIFont.boldSystemFont(ofSize: 25)
}
if italic {
    attributes[.font] = UIFont.italicSystemFont(ofSize: CGFloat(fontSize))
}
if underline {
    attributes[.underlineStyle] = 1
}

let attributedString = NSAttributedString(string: string, attributes: attributes)
// Other Code