ios - 使用 Swift 从 NSString 中查找 String 作为 NSRange 的出现，结果 NSRange 将在 NSAttributedString 中使用

Question

我试图在一个字符串中查找多个字符串的 NSRange。

在下面的代码中，我使用 String.range(of: String, options: , Range) 方法找到 Range，并转换为 NSRange。当文本包含多代码单元 unicode 字符时，此转换失败，例如表情符号:

let findInString = "This #is a #tag #tag inten#sive🔦#search" // MAY CONTAINS EMOJIS
let findStrings = ["#is","#tag","#sive","#search"]
let result = NSMutableAttributedString(string: findInString)

for (index, stringToFind) in findStrings.enumerated() {

    var nextStartIndex = findInString.startIndex

    while let range = findInString.range(of: stringToFind, options: [.literal, .caseInsensitive], range: nextStartIndex..<findInString.endIndex) {

        let start = findInString.distance(from: findInString.startIndex, to: range.lowerBound)
        let length = findInString.distance(from: range.lowerBound, to: range.upperBound)

        result.addAttribute(NSLinkAttributeName, value: "\(index):", range: NSMakeRange(start, length))

        nextStartIndex = range.upperBound
    }

}

问题:它会工作吗 如果我使用 NSString.range() 来查找 NSRange。我正在尝试这样做，但我的以下代码在 range: 部分有错误。

let findInNsString = findInString as NSString
while let range = findInNsString.range(of: stringToFind, options: [.literal, .caseInsensitive], range: nextStartIndex..<findInString.endIndex)

我需要帮助来理解和更正上述错误，在此先感谢。

Answer 1

找到了将 Range 转换为 NSRange 的正确方法，感谢 MartinR 提供的 answer

我使用错误的方式将 Range 转换为 NSRange，这里是工作代码片段，以正确的方式将 Range 转换为NSRange:

let findStrings = ["#is","#tag","#siØve","#search"]
let findInString = "This #is a #tag #tag inten#siØve🔦#search"
let result = NSMutableAttributedString(string: findInString)
let utf16 = findInString.utf16
for (index, stringToFind) in findStrings.enumerated() {

    var nextStartIndex = findInString.startIndex

    while let range = findInString.range(of: stringToFind, options: [.literal, .caseInsensitive], range: nextStartIndex..<findInString.endIndex) {

        // PROPER WAY TO CONVERT TO NSRange
        let from = range.lowerBound.samePosition(in: utf16)
        let start = utf16.distance(from: utf16.startIndex, to: from)
        let length = utf16.distance(from: from, to: range.upperBound.samePosition(in: utf16))

        result.addAttribute(NSLinkAttributeName, value: "\(index):", range: NSMakeRange(start, length))

        nextStartIndex = range.upperBound
    }

}