如何在NSAttributedString中使用NSAttributedString？

Question

在NSAttributed类型语句中，我希望保留现有的属性值，并给它一个新的属性值。

问题是，replacingOccurrences只可能用于字符串类型，因为每当单词出现在整个句子中时，我都想给出一个新的值。

如果我将NSAttributedString更改为字符串类型，则属性化值将被删除。我必须保持现有的价值观。

我怎么能这么做？

Answer 1

为了让这件事奏效，

1.首先需要找到字符串中存在的所有重复子字符串的索引。要获得这个结果，您可以使用以下内容：https://stackoverflow.com/a/40413665/5716829

extension String {
    func indicesOf(string: String) -> [Int] {
        var indices = [Int]()
        var searchStartIndex = self.startIndex

        while searchStartIndex < self.endIndex,
            let range = self.range(of: string, range: searchStartIndex..<self.endIndex),
            !range.isEmpty
        {
            let index = distance(from: self.startIndex, to: range.lowerBound)
            indices.append(index)
            searchStartIndex = range.upperBound
        }

        return indices
    }
}

2.下一步您需要将所需的属性应用于每个索引的子字符串，即

    let str = "The problem is that replacingOccurrences Hello is only possible for string types, as I want to give Hello a new value every time Hello the word appears in the entire sentence Hello."
    let indices = str.indicesOf(string: "Hello")
    let attrStr = NSMutableAttributedString(string: str, attributes: [.foregroundColor : UIColor.blue])
    for index in indices
    {
        //You can write your own logic to specify the color for each duplicate. I have used some hardcode indices
        var color: UIColor
        switch index
        {
        case 41:
            color = .orange
        case 100:
            color = .magenta
        case 129:
            color = .green
        default:
            color = .red
        }
        attrStr.addAttribute(.foregroundColor, value: color, range: NSRange(location: index, length: "Hello".count))
    }

截图：

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如果你还面临任何问题请告诉我。快乐编码..。

Answer 2

您可以使用replaceCharacters。您可以找到要删除的子字符串的范围，并将其用作您的范围。