更改属性字符串的文本并在Swift中保留属性 [英] Change text of an attributed string and retain attributes in Swift

问题描述

对于数据库程序中的输出，我有一些文本，我已经插入一些标记以指示粗体或斜体，以及一些替代图像的文本.例如:

For output in a database program, I have certain text that I've inserted marks to indicate bold or italics, as well as some text that is substituted for images. For instance:

％重要％^所有进入休息室的员工^"的最终输出应为:

"%Important% ^All employees to the breakroom^" should have final output as:

重要 所有进入休息室的员工

我编写了代码来查找带有％"符号和"^"符号的文本，但是现在遇到的麻烦是文本输出，如:

I have code written to find the text with "%" signs around it and "^" signs, but the trouble I have now is the text outputs like:

％重要％ ^ 所有进入休息室的员工 ^

我想在保留字符串格式的同时删除这些％和^.

I'd like to remove these % and ^'s while retaining the string's formatting.

这是我用完直到崩溃的代码:

This is the code I'm using up until it breaks:

func processText(inString string: String) -> NSAttributedString {

let pattern = ["(?<=\\^).*?(?=\\^)","(?<=\\%).*?(?=\\%)","\\^", "\\%"]
let italicsRegex = NSRegularExpression(pattern: pattern[0], options: .allZeros, error: nil)
let range = NSMakeRange(0, count(string))
let italicsMatches = italicsRegex?.matchesInString(string, options: .allZeros, range: range) as? [NSTextCheckingResult]

var attributedText = NSMutableAttributedString(string: string)

for match in italicsMatches! {
    attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "Helvetica-Oblique", size: 14.0)!, range: match.range)
}

let boldRegex = NSRegularExpression(pattern: pattern[1], options: .allZeros, error: nil)
let boldMatches = boldRegex?.matchesInString(string, options: .allZeros, range: range) as? [NSTextCheckingResult]

for match in boldMatches!   {
    attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "Helvetica-Bold", size: 14.0)!, range: match.range)
}

let removeItalicsMarksRegex = NSRegularExpression(pattern: pattern[2], options: .allZeros, error: nil)
let removeItalicsMarksMatches = removeItalicsMarksRegex?.matchesInString(string, options: .allZeros, range: range) as? [NSTextCheckingResult]

var numberOfLoops = 0
for match in removeItalicsMarksMatches! {

    attributedText.replaceCharactersInRange(match.range, withString: "")

}

return attributedText.copy() as! NSAttributedString
}

这适用于％匹配(但仅第一个字符)，并立即导致^字符崩溃.

This works for the % match (but only the first character) and causes a crash on the ^ character immediately.

任何解决此问题的帮助或建议，将不胜感激.谢谢.

Any help or advice with resolving this would be appreciated. Thanks.

推荐答案

马丁，

我最终使用了非常相似的东西，但是我决定更改正则表达式以包含^标记.这样，我便可以使用"replaceCharactersInRange"方法剪辑所包含的属性子字符串的第一个和最后一个字符.到目前为止，这对于我的目的来说要好一些，因为它是在属性字符串中工作的，因此不会弄乱或删除其任何属性.

I ended up using something very similar, but I decided to change the regular expression to include the ^ marks. In doing so, I was able to then clip the first and last characters of the included attributed substring with the "replaceCharactersInRange" method. This works a little better for my purposes so far because it's working from the attributed string so it doesn't screw up or remove any of its attributes.

我已将正则表达式和处理斜体的代码部分附加在一起，以供将来任何人参考(并再次感谢！):

I've attached the regex and the portion of the code that deals with italics for anyone's future reference (and thanks, again!):

func processText(inString string: String) -> NSAttributedString {

let pattern = ["\\^.*?\\^"] //Presented as an array here because in the full code there are a lot of patterns that are run.




let italicsRegex = NSRegularExpression(pattern: pattern[0], options: .allZeros, error: nil) 

//In addition to building the match for this first regular expression, I also gather build the regular expressions and gather matches for all other matching patterns on the initial string ("string") before I start doing any processing.

    let range = NSMakeRange(0, count(string.utf16))

let italicsMatches = italicsRegex?.matchesInString(string, options: .allZeros, range: range) as? [NSTextCheckingResult]

var attributedText = NSMutableAttributedString(string: string)

var charactersRemovedFromString = 0

for match in italicsMatches! {

    let newRange = NSMakeRange(match.range.location - charactersRemovedFromString, match.range.length) // Take the updated range for when this loop iterates, otherwise this crashes.
    attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "Helvetica-Oblique", size: 12.0)!, range: newRange)

    let rangeOfFirstCharacter = NSMakeRange(match.range.location - charactersRemovedFromString, 1)

    attributedText.replaceCharactersInRange(rangeOfFirstCharacter, withString: "")

    charactersRemovedFromString += 2

    let rangeOfLastCharacter = NSMakeRange(match.range.location + match.range.length - charactersRemovedFromString, 1)

    attributedText.replaceCharactersInRange(rangeOfLastCharacter, withString: "")
    }

return attributedText
}

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