如何从完整字符串iOS Swift中为一个字符串查找多个NSRange

Question

let fullString = "Hello world, there are \(string(07)) continents and \(string(195)) countries."
let range = [NSMakeRange(24,2), NSMakeRange(40,3)]

需要在整个完整字符串中找到数字的NSRange，并且两个数字可能相同。 当前如上所示的硬编码，该消息可以是动态的，其中硬编码值将是有问题的。

我已经拆分了字符串，并尝试获取NSRange因为可能存在相同的值。 像stringOne和stringTwo。

func findNSMakeRange(initialString:String, fromString: String) {
        let fullStringRange = fromString.startIndex..<fromString.endIndex
        fromString.enumerateSubstrings(in: fullStringRange, options: NSString.EnumerationOptions.byWords) { (substring, substringRange, enclosingRange, stop) -> () in
            let start = distance(fromString.startIndex, substringRange.startIndex)
            let length = distance(substringRange.startIndex, substringRange.endIndex)
            let range = NSMakeRange(start, length)

            if (substring == initialString) {
                print(substring, range)
            }
        })
    }

接收到诸如Cannot invoke distance with an argument list of type (String.Index, String.Index)错误

有人有更好的解决方案吗？

Answer 1

另一种方法是定义扩展以返回范围数组，即[Range<String.Index>] ：

extension StringProtocol where Index == String.Index {
    func ranges<T: StringProtocol>(of string: T, options: String.CompareOptions = []) -> [Range<Index>] {
        var ranges: [Range<Index>] = []
        var start: Index = startIndex

        while let range = range(of: string, options: options, range: start..<endIndex) {
            ranges.append(range)
            start = range.upperBound
        }

        return ranges
    }
}

然后，您可以像这样使用它：

let string = "Hello world, there are 09 continents and 195 countries."
let ranges = string.ranges(of: "[0-9]+", options: .regularExpression)

因此，例如，如果您想在某些属性字符串中将这些数字设为粗体：

string.ranges(of: "[0-9]+", options: .regularExpression)
    .map { NSRange($0, in: string) }
    .forEach {
        attributedString.setAttributes(boldAttributes, range: $0)
}