Calculate range of string from word to end of string in swift

问题

I have an NSMutatableString:

var string: String = "Due in %@ (%@) $%@.\nOverdue! Please pay now %@"
attributedText = NSMutableAttributedString(string: string, attributes: attributes)

How to calculate both the length and starting index from the word Overdue in swift?

so far I have tried:

let startIndex = attributedText.string.rangeOfString("Overdue")
let range = startIndex..<attributedText.string.finishIndex

// Access the substring.
let substring = value[range]
print(substring)

But it doesn't work.

回答1:

You should generate the resulting string first:

let string = String(format: "Due in %@ (%@) $%@.\nOverdue! Please pay now %@", "some date", "something", "15", "some date")

Then use .disTanceTo to get the distance between indices;

if let range = string.rangeOfString("Overdue") {
  let start = string.startIndex.distanceTo(range.startIndex)
  let length = range.startIndex.distanceTo(string.endIndex)

  let wordToEndRange = NSRange(location: start, length: length) 
  // This is the range you need

  attributedText.addAttribute(NSForegroundColorAttributeName, 
     value: UIColor.blueColor(), range: wordToEndRange)
}

Please do note that NSRange does not work correctly if the string contains Emojis or other Unicode characters so that the above solution may not work properly for that case.

Please look at the following SO answers for a better solution which cover that case as well:

https://stackoverflow.com/a/27041376/793428
https://stackoverflow.com/a/27880748/793428

来源：https://stackoverflow.com/questions/39340898/calculate-range-of-string-from-word-to-end-of-string-in-swift

标签

swift

nsrange