NSRange 到 Range<String.Index> [英] NSRange to Range&lt;String.Index&gt;

问题描述

如何在 Swift 中将 NSRange 转换为 Range?

How can I convert NSRange to Range<String.Index> in Swift?

我想使用以下 UITextFieldDelegate 方法:

I want to use the following UITextFieldDelegate method:

    func textField(textField: UITextField!,
        shouldChangeCharactersInRange range: NSRange,
        replacementString string: String!) -> Bool {

textField.text.stringByReplacingCharactersInRange(???, withString: string)

推荐答案

replacingCharacters(in: NSRange, with: NSString)NSString 版本(相对于 Swift String)code> 接受一个 NSRange，因此一个简单的解决方案是先将 String 转换为 NSString.Swift 3 和 2 中的委托和替换方法名称略有不同，因此取决于您使用的是哪种 Swift:

The NSString version (as opposed to Swift String) of replacingCharacters(in: NSRange, with: NSString) accepts an NSRange, so one simple solution is to convert String to NSString first. The delegate and replacement method names are slightly different in Swift 3 and 2, so depending on which Swift you're using:

func textField(_ textField: UITextField,
               shouldChangeCharactersIn range: NSRange,
               replacementString string: String) -> Bool {

  let nsString = textField.text as NSString?
  let newString = nsString?.replacingCharacters(in: range, with: string)
}

斯威夫特 2.x

func textField(textField: UITextField,
               shouldChangeCharactersInRange range: NSRange,
               replacementString string: String) -> Bool {

    let nsString = textField.text as NSString?
    let newString = nsString?.stringByReplacingCharactersInRange(range, withString: string)
}

这篇关于NSRange 到 Range<String.Index>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！